diff --git a/conda_build/api.py b/conda_build/api.py
index fb8555c07c..b64c14002e 100644
--- a/conda_build/api.py
+++ b/conda_build/api.py
@@ -11,11 +11,14 @@
 
 from __future__ import annotations
 
+import inspect
+
 # imports are done locally to keep the api clean and limited strictly
 #    to conda-build's functionality.
 import os
 import sys
 from collections.abc import Iterable
+from importlib import import_module
 from os.path import dirname, expanduser, join
 from pathlib import Path
 from typing import TYPE_CHECKING
@@ -23,6 +26,7 @@
 # make the Config class available in the api namespace
 from .config import DEFAULT_PREFIX_LENGTH as _prefix_length
 from .config import Config, get_channel_urls, get_or_merge_config
+from .deprecations import deprecated
 from .metadata import MetaData, MetaDataTuple
 from .utils import (
     CONDA_PACKAGE_EXTENSIONS,
@@ -259,6 +263,7 @@ def test(
         )
 
 
+@deprecated("27.3", "27.9", addendum="Use `grayskull` instead.")
 def list_skeletons() -> list[str]:
     """List available skeletons for generating conda recipes from external sources.
 
@@ -274,6 +279,7 @@ def list_skeletons() -> list[str]:
     return files
 
 
+@deprecated("27.3", "27.9", addendum="Use `grayskull` instead.")
 def skeletonize(
     packages: str | Iterable[str],
     repo: Literal["cpan", "cran", "luarocks", "pypi", "rpm"],
@@ -306,18 +312,13 @@ def skeletonize(
     #    off of the config object, and pass it as a keyword argument.  This is sort of the
     #    inverse of what we do in the CLI code - there we take CLI arguments and dangle them
     #    all on the config object as attributes.
-    module = getattr(
-        __import__(
-            "conda_build.skeletons", globals=globals(), locals=locals(), fromlist=[repo]
-        ),
-        repo,
-    )
-
-    func_args = module.skeletonize.__code__.co_varnames
+    module = import_module(f"conda_build.skeletons.{repo}")
+    argspec = inspect.signature(module.skeletonize)
+    func_args = list(argspec.parameters)
     kwargs = {name: getattr(config, name) for name in dir(config) if name in func_args}
     kwargs.update({name: value for name, value in kwargs.items() if name in func_args})
     # strip out local arguments that we pass directly
-    for arg in skeletonize.__code__.co_varnames:
+    for arg in list(inspect.signature(skeletonize).parameters):
         if arg in kwargs:
             del kwargs[arg]
     with config:
diff --git a/conda_build/cli/main_skeleton.py b/conda_build/cli/main_skeleton.py
index 66a93cef63..eeda7f428f 100644
--- a/conda_build/cli/main_skeleton.py
+++ b/conda_build/cli/main_skeleton.py
@@ -13,6 +13,7 @@
 
 from .. import api
 from ..config import Config
+from ..deprecations import deprecated
 
 if TYPE_CHECKING:
     from argparse import ArgumentParser, Namespace
@@ -21,6 +22,8 @@
 thisdir = os.path.dirname(os.path.abspath(__file__))
 logging.basicConfig(level=logging.INFO)
 
+deprecated.module("27.3", "27.9", addendum="Use the `grayskull` tool instead.")
+
 
 def parse_args(args: Sequence[str] | None) -> tuple[ArgumentParser, Namespace]:
     from conda.cli.conda_argparse import ArgumentParser
@@ -30,6 +33,7 @@ def parse_args(args: Sequence[str] | None) -> tuple[ArgumentParser, Namespace]:
         description="""
 Generates a boilerplate/skeleton recipe, which you can then edit to create a
 full recipe. Some simple skeleton recipes may not even need edits.
+Pending deprecation. Please use the `grayskull` tool instead: https://conda.github.io/grayskull
         """,
         epilog="""
 Run --help on the subcommands like 'conda skeleton pypi --help' to see the
@@ -52,6 +56,7 @@ def parse_args(args: Sequence[str] | None) -> tuple[ArgumentParser, Namespace]:
     return parser, parser.parse_args(args)
 
 
+@deprecated("27.3", "27.9", addendum="Use `grayskull` instead.")
 def execute(args: Sequence[str] | None = None) -> int:
     parser, parsed = parse_args(args)
     context.__init__(argparse_args=parsed)
diff --git a/conda_build/skeletons/cpan.py b/conda_build/skeletons/cpan.py
index 58c806493b..9027feec08 100644
--- a/conda_build/skeletons/cpan.py
+++ b/conda_build/skeletons/cpan.py
@@ -29,6 +29,7 @@
 
 from .. import environ
 from ..config import Config, get_or_merge_config
+from ..deprecations import deprecated
 from ..utils import check_call_env, on_linux, on_win
 from ..variants import get_default_variant
 from ..version import _parse as parse_version
@@ -384,6 +385,7 @@ def get_core_modules_for_this_perl_version(version, cache_dir):
     )
 
 
+@deprecated("27.3", "27.9", addendum="Use `grayskull` instead.")
 # meta_cpan_url="http://api.metacpan.org",
 def skeletonize(
     packages: list[str],
diff --git a/conda_build/skeletons/cran.py b/conda_build/skeletons/cran.py
index 152c3617ad..3248620ea0 100755
--- a/conda_build/skeletons/cran.py
+++ b/conda_build/skeletons/cran.py
@@ -33,6 +33,8 @@
 import requests
 import yaml
 
+from ..deprecations import deprecated
+
 # try to import C dumper
 try:
     from yaml import CSafeDumper as SafeDumper
@@ -864,6 +866,7 @@ def remove_comments(template):
     return "\n".join(lines_no_comments)
 
 
+@deprecated("27.3", "27.9", addendum="Use `grayskull` instead.")
 def skeletonize(
     in_packages: list[str],
     output_dir: str = ".",
diff --git a/conda_build/skeletons/luarocks.py b/conda_build/skeletons/luarocks.py
index 41ec499bad..3f6ec35ad8 100644
--- a/conda_build/skeletons/luarocks.py
+++ b/conda_build/skeletons/luarocks.py
@@ -17,6 +17,8 @@
 from glob import glob
 from sys import platform as _platform
 
+from ..deprecations import deprecated
+
 INDENT = "\n    - "
 
 rockspec_parser = """
@@ -226,6 +228,7 @@ def ensure_base_deps(deps):
     return deps
 
 
+@deprecated("27.3", "27.9", addendum="Use `grayskull` instead.")
 def skeletonize(
     packages: list[str],
     output_dir: str = ".",
diff --git a/conda_build/skeletons/pypi.py b/conda_build/skeletons/pypi.py
index ed4aeb5a9d..c514706423 100644
--- a/conda_build/skeletons/pypi.py
+++ b/conda_build/skeletons/pypi.py
@@ -34,6 +34,7 @@
 from requests.packages.urllib3.util.url import parse_url
 
 from ..config import Config
+from ..deprecations import deprecated
 from ..environ import create_env
 from ..license_family import allowed_license_families, guess_license_family
 from ..metadata import MetaData
@@ -258,6 +259,7 @@ def _formating_value(attribute_name, attribute_value):
     return " " + str(attribute_value) + "\n"
 
 
+@deprecated("27.3", "27.9", addendum="Use `grayskull` instead.")
 def skeletonize(
     packages: list[str],
     output_dir: str = ".",
diff --git a/conda_build/skeletons/rpm.py b/conda_build/skeletons/rpm.py
index 0ac211a2f8..8b0f0caf22 100644
--- a/conda_build/skeletons/rpm.py
+++ b/conda_build/skeletons/rpm.py
@@ -15,6 +15,7 @@
 from urllib.request import urlopen
 from xml.etree import ElementTree as ET
 
+from ..deprecations import deprecated
 from ..license_family import guess_license_family
 from ..source import download_to_cache
 from ..utils import ensure_list
@@ -714,6 +715,7 @@ def write_conda_recipe(
         )
 
 
+@deprecated("27.3", "27.9", addendum="Use `grayskull` instead.")
 def skeletonize(
     packages: list[str],
     output_dir: str = ".",
diff --git a/news/6023-conda-skeleton-deprecation.md b/news/6023-conda-skeleton-deprecation.md
new file mode 100644
index 0000000000..465de877fd
--- /dev/null
+++ b/news/6023-conda-skeleton-deprecation.md
@@ -0,0 +1,19 @@
+### Enhancements
+
+* <news item>
+
+### Bug fixes
+
+* <news item>
+
+### Deprecations
+
+* Mark `conda skeleton` as pending deprecation, with removal scheduled in 27.9 release. Users are encouraged to use [grayskull](https://conda.github.io/grayskull) instead of `conda skeleton`. (#4460 via #6023)
+
+### Docs
+
+* <news item>
+
+### Other
+
+* <news item>
diff --git a/tests/cli/test_main_skeleton.py b/tests/cli/test_main_skeleton.py
index a20e91605a..d779922290 100644
--- a/tests/cli/test_main_skeleton.py
+++ b/tests/cli/test_main_skeleton.py
@@ -1,5 +1,6 @@
 # Copyright (C) 2014 Anaconda, Inc
 # SPDX-License-Identifier: BSD-3-Clause
+import importlib
 import os
 import re
 from pathlib import Path
@@ -13,7 +14,8 @@
 @pytest.mark.sanity
 def test_skeleton_pypi(testing_workdir, testing_config):
     args = ["pypi", "peppercorn"]
-    main_skeleton.execute(args)
+    with pytest.deprecated_call():
+        main_skeleton.execute(args)
     assert os.path.isdir("peppercorn")
 
     # add setuptools to host dependencies
@@ -34,7 +36,8 @@ def test_skeleton_pypi(testing_workdir, testing_config):
 @pytest.mark.sanity
 def test_skeleton_pypi_compatible_versions(testing_workdir, testing_config):
     args = ["pypi", "openshift"]
-    main_skeleton.execute(args)
+    with pytest.deprecated_call():
+        main_skeleton.execute(args)
     assert os.path.isdir("openshift")
 
 
@@ -48,7 +51,8 @@ def test_skeleton_pypi_arguments_work(testing_workdir):
     https://github.com/conda/conda-build/pull/1384
     """
     args = ["pypi", "fasttext", "--version=0.9.2", "--pin-numpy"]
-    main_skeleton.execute(args)
+    with pytest.deprecated_call():
+        main_skeleton.execute(args)
     assert os.path.isdir("fasttext")
 
     # Deliberately bypass metadata reading in conda build to get as
@@ -63,10 +67,23 @@ def test_skeleton_pypi_arguments_work(testing_workdir):
         "--setup-options=--offline",
         "--extra-specs=extension-helpers",
     ]
-    main_skeleton.execute(args)
+    with pytest.deprecated_call():
+        main_skeleton.execute(args)
     assert os.path.isdir("photutils")
     # Check that the setup option occurs in bld.bat and build.sh.
 
     metadata = api.render("photutils")[0][0]
     assert "--offline" in metadata.meta["build"]["script"]
     assert metadata.version() == "1.10.0"
+
+
+def test_skeleton_deprecation_warning():
+    """
+    Verify that importing conda_build.cli.main_skeleton will raise a deprecation warning.
+    """
+    with pytest.deprecated_call(
+        match=r"conda_build.cli.main_skeleton is pending deprecation.*grayskull.*",
+    ):
+        import conda_build.cli.main_skeleton  # noqa F401
+
+        importlib.reload(conda_build.cli.main_skeleton)
diff --git a/tests/test_api_consistency.py b/tests/test_api_consistency.py
index 9dac14351c..005803c757 100644
--- a/tests/test_api_consistency.py
+++ b/tests/test_api_consistency.py
@@ -2,6 +2,7 @@
 # SPDX-License-Identifier: BSD-3-Clause
 # This file makes sure that our API has not changed.  Doing so can not be accidental.  Whenever it
 #    happens, we should bump our major build number, because we may have broken someone.
+import inspect
 import sys
 from inspect import getfullargspec as getargspec
 
@@ -86,22 +87,25 @@ def test_api_test():
 
 
 def test_api_list_skeletons():
-    argspec = getargspec(api.list_skeletons)
-    assert argspec.args == []
-    assert argspec.defaults is None
+    sig = inspect.signature(api.list_skeletons)
+    assert list(sig.parameters) == []
+    assert all(p.default is inspect._empty for p in sig.parameters.values())
 
 
 def test_api_skeletonize():
-    argspec = getargspec(api.skeletonize)
-    assert argspec.args == [
+    sig = inspect.signature(api.skeletonize)
+    assert list(sig.parameters) == [
         "packages",
         "repo",
         "output_dir",
         "version",
         "recursive",
         "config",
+        "kwargs",
     ]
-    assert argspec.defaults == (".", None, False, None)
+    assert tuple(
+        p.default for p in sig.parameters.values() if p.default is not inspect._empty
+    ) == (".", None, False, None)
 
 
 def test_api_develop():
diff --git a/tests/test_api_skeleton.py b/tests/test_api_skeleton.py
index 1e605a75a0..aec14be256 100644
--- a/tests/test_api_skeleton.py
+++ b/tests/test_api_skeleton.py
@@ -202,13 +202,14 @@ def test_repo(
     tmp_path: Path,
     testing_config,
 ):
-    api.skeletonize(
-        package,
-        repo,
-        version=version,
-        output_dir=tmp_path,
-        config=testing_config,
-    )
+    with pytest.deprecated_call():
+        api.skeletonize(
+            package,
+            repo,
+            version=version,
+            output_dir=tmp_path,
+            config=testing_config,
+        )
 
     package_name = f"{prefix}{Path(package).stem}".lower()
     assert len(
@@ -228,13 +229,14 @@ def test_repo(
     ],
 )
 def test_sympy(package: str, version: str | None, tmp_path: Path, testing_config):
-    api.skeletonize(
-        packages=package,
-        repo="pypi",
-        version=version,
-        config=testing_config,
-        output_dir=tmp_path,
-    )
+    with pytest.deprecated_call():
+        api.skeletonize(
+            packages=package,
+            repo="pypi",
+            version=version,
+            config=testing_config,
+            output_dir=tmp_path,
+        )
     metadata = api.render(str(tmp_path / "sympy" / "meta.yaml"))[0][0]
     assert metadata.version() == "1.10"
 
@@ -340,15 +342,16 @@ def test_pypi_with_setup_options(tmp_path: Path, testing_config):
     # occurs by default.
 
     # Test that the setup option is used in constructing the skeleton.
-    api.skeletonize(
-        packages="photutils",
-        repo="pypi",
-        version="1.10.0",
-        setup_options="--offline",
-        config=testing_config,
-        output_dir=tmp_path,
-        extra_specs=["extension-helpers"],
-    )
+    with pytest.deprecated_call():
+        api.skeletonize(
+            packages="photutils",
+            repo="pypi",
+            version="1.10.0",
+            setup_options="--offline",
+            config=testing_config,
+            output_dir=tmp_path,
+            extra_specs=["extension-helpers"],
+        )
 
     # Check that the setup option occurs in bld.bat and build.sh.
     metadata = api.render(str(tmp_path / "photutils"))[0][0]
@@ -358,50 +361,55 @@ def test_pypi_with_setup_options(tmp_path: Path, testing_config):
 def test_pypi_pin_numpy(tmp_path: Path, testing_config: Config):
     # The package used here must have a numpy dependence for pin-numpy to have
     # any effect.
-    api.skeletonize(
-        packages="fasttext",
-        repo="pypi",
-        version="0.9.2",
-        config=testing_config,
-        pin_numpy=True,
-        output_dir=tmp_path,
-    )
+    with pytest.deprecated_call():
+        api.skeletonize(
+            packages="fasttext",
+            repo="pypi",
+            version="0.9.2",
+            config=testing_config,
+            pin_numpy=True,
+            output_dir=tmp_path,
+        )
     assert (tmp_path / "fasttext" / "meta.yaml").read_text().count("numpy x.x") == 2
 
 
 def test_pypi_version_sorting(tmp_path: Path, testing_config: Config):
     # The package used here must have a numpy dependence for pin-numpy to have
     # any effect.
-    api.skeletonize(
-        packages="fasttext",
-        repo="pypi",
-        config=testing_config,
-        output_dir=tmp_path,
-    )
+    with pytest.deprecated_call():
+        api.skeletonize(
+            packages="fasttext",
+            repo="pypi",
+            config=testing_config,
+            output_dir=tmp_path,
+        )
     metadata = api.render(str(tmp_path / "fasttext"))[0][0]
     assert parse_version(metadata.version()) >= parse_version("0.9.2")
 
 
 def test_list_skeletons():
-    skeletons = api.list_skeletons()
+    with pytest.deprecated_call():
+        skeletons = api.list_skeletons()
     assert set(skeletons) == {"pypi", "cran", "cpan", "luarocks", "rpm"}
 
 
 def test_pypi_with_entry_points(tmp_path: Path):
     # planemo 0.75.29 dropped setup.py
-    api.skeletonize(
-        "planemo",
-        repo="pypi",
-        version="0.75.28",
-        python_version="3.12",
-        output_dir=tmp_path,
-    )
+    with pytest.deprecated_call():
+        api.skeletonize(
+            "planemo",
+            repo="pypi",
+            version="0.75.28",
+            python_version="3.12",
+            output_dir=tmp_path,
+        )
     assert (tmp_path / "planemo").is_dir()
 
 
 def test_pypi_with_version_arg(tmp_path: Path):
     # regression test for https://github.com/conda/conda-build/issues/1442
-    api.skeletonize("PrettyTable", "pypi", version="0.7.2", output_dir=tmp_path)
+    with pytest.deprecated_call():
+        api.skeletonize("PrettyTable", "pypi", version="0.7.2", output_dir=tmp_path)
     metadata = api.render(str(tmp_path / "prettytable"))[0][0]
     assert parse_version(metadata.version()) == parse_version("0.7.2")
 
@@ -418,15 +426,16 @@ def test_pypi_with_extra_specs(tmp_path: Path, testing_config):
     extra_specs = ["cython", "mpi4py"]
     if not on_win:
         extra_specs.append("nomkl")
-    api.skeletonize(
-        "bigfile",
-        "pypi",
-        extra_specs=extra_specs,
-        version="0.1.24",
-        python="3.6",
-        config=testing_config,
-        output_dir=tmp_path,
-    )
+    with pytest.deprecated_call():
+        api.skeletonize(
+            "bigfile",
+            "pypi",
+            extra_specs=extra_specs,
+            version="0.1.24",
+            python="3.6",
+            config=testing_config,
+            output_dir=tmp_path,
+        )
     metadata = api.render(str(tmp_path / "bigfile"))[0][0]
     assert parse_version(metadata.version()) == parse_version("0.1.24")
     assert any("cython" in req for req in metadata.meta["requirements"]["host"])
@@ -445,22 +454,24 @@ def test_pypi_with_version_inconsistency(tmp_path: Path, testing_config):
     if not on_win:
         extra_specs.append("nomkl")
     testing_config.channel_urls.append("https://repo.anaconda.com/pkgs/free")
-    api.skeletonize(
-        "mpi4py_test",
-        "pypi",
-        extra_specs=extra_specs,
-        version="0.0.10",
-        python="3.6",
-        config=testing_config,
-        output_dir=tmp_path,
-    )
+    with pytest.deprecated_call():
+        api.skeletonize(
+            "mpi4py_test",
+            "pypi",
+            extra_specs=extra_specs,
+            version="0.0.10",
+            python="3.6",
+            config=testing_config,
+            output_dir=tmp_path,
+        )
     metadata = api.render(str(tmp_path / "mpi4py_test"))[0][0]
     assert parse_version(metadata.version()) == parse_version("0.0.10")
 
 
 def test_pypi_with_basic_environment_markers(tmp_path: Path):
     # regression test for https://github.com/conda/conda-build/issues/1974
-    api.skeletonize("coconut", "pypi", version="1.2.2", output_dir=tmp_path)
+    with pytest.deprecated_call():
+        api.skeletonize("coconut", "pypi", version="1.2.2", output_dir=tmp_path)
     metadata = api.render(tmp_path / "coconut")[0][0]
 
     build_reqs = str(metadata.meta["requirements"]["host"])
@@ -473,9 +484,10 @@ def test_pypi_with_basic_environment_markers(tmp_path: Path):
 
 
 def test_setuptools_test_requirements(tmp_path: Path):
-    api.skeletonize(
-        packages="hdf5storage", repo="pypi", version="0.1.19", output_dir=tmp_path
-    )
+    with pytest.deprecated_call():
+        api.skeletonize(
+            packages="hdf5storage", repo="pypi", version="0.1.19", output_dir=tmp_path
+        )
     metadata = api.render(str(tmp_path / "hdf5storage"))[0][0]
     assert metadata.meta["test"]["requires"] == ["nose >=1.0"]
 
@@ -492,7 +504,8 @@ def test_pypi_section_order_preserved(tmp_path: Path):
         REQUIREMENTS_ORDER,
     )
 
-    api.skeletonize(packages="sympy", repo="pypi", output_dir=tmp_path)
+    with pytest.deprecated_call():
+        api.skeletonize(packages="sympy", repo="pypi", output_dir=tmp_path)
     # Since we want to check the order of items in the recipe (not whether
     # the metadata values themselves are sensible), read the file as (ordered)
     # yaml, and check the order.
@@ -532,12 +545,13 @@ def test_pypi_section_order_preserved(tmp_path: Path):
 def test_build_sh_shellcheck_clean(
     package: str, repo: str, tmp_path: Path, testing_config
 ):
-    api.skeletonize(
-        packages=package,
-        repo=repo,
-        output_dir=tmp_path,
-        config=testing_config,
-    )
+    with pytest.deprecated_call():
+        api.skeletonize(
+            packages=package,
+            repo=repo,
+            output_dir=tmp_path,
+            config=testing_config,
+        )
 
     build_sh = next(
         Path(root, filename)
diff --git a/tests/test_api_skeleton_cpan.py b/tests/test_api_skeleton_cpan.py
index 5945158023..a32fa02298 100644
--- a/tests/test_api_skeleton_cpan.py
+++ b/tests/test_api_skeleton_cpan.py
@@ -16,7 +16,10 @@
 def test_xs_needs_c_compiler(testing_config):
     """Perl packages with XS files need a C compiler"""
     # This uses Sub::Identify=0.14 since it includes no .c files but a .xs file.
-    api.skeletonize("Sub::Identify", version="0.14", repo="cpan", config=testing_config)
+    with pytest.deprecated_call():
+        api.skeletonize(
+            "Sub::Identify", version="0.14", repo="cpan", config=testing_config
+        )
     metadata = api.render(
         "perl-sub-identify/0.14", finalize=False, bypass_env_check=True
     )[0][0]
diff --git a/tests/test_api_skeleton_cran.py b/tests/test_api_skeleton_cran.py
index 6344e95c1e..11afe56403 100644
--- a/tests/test_api_skeleton_cran.py
+++ b/tests/test_api_skeleton_cran.py
@@ -38,9 +38,10 @@ def test_cran_license(
     tmp_path: Path,
     testing_config,
 ):
-    api.skeletonize(
-        packages=package, repo="cran", output_dir=tmp_path, config=testing_config
-    )
+    with pytest.deprecated_call():
+        api.skeletonize(
+            packages=package, repo="cran", output_dir=tmp_path, config=testing_config
+        )
     metadata = api.render(str(tmp_path / package / "meta.yaml"))[0][0]
 
     assert metadata.get_value("about/license") == license_id
@@ -60,9 +61,10 @@ def test_cran_license(
 )
 @pytest.mark.flaky(rerun=5, reruns_delay=2)
 def test_cran_os_type(package: str, skip_text: str, tmp_path: Path, testing_config):
-    api.skeletonize(
-        packages=package, repo="cran", output_dir=tmp_path, config=testing_config
-    )
+    with pytest.deprecated_call():
+        api.skeletonize(
+            packages=package, repo="cran", output_dir=tmp_path, config=testing_config
+        )
     assert skip_text in (tmp_path / f"r-{package.lower()}" / "meta.yaml").read_text()
 
 
@@ -79,13 +81,14 @@ def test_cran_no_comments(tmp_path: Path, testing_config):
     assert build_sh_comment in CRAN_BUILD_SH_SOURCE
     assert build_sh_shebang in CRAN_BUILD_SH_SOURCE
 
-    api.skeletonize(
-        packages=package,
-        repo="cran",
-        output_dir=tmp_path,
-        config=testing_config,
-        no_comments=True,
-    )
+    with pytest.deprecated_call():
+        api.skeletonize(
+            packages=package,
+            repo="cran",
+            output_dir=tmp_path,
+            config=testing_config,
+            no_comments=True,
+        )
 
     # Check that comments got removed
     meta_yaml_text = (tmp_path / f"r-{package.lower()}" / "meta.yaml").read_text()