diff --git a/pkg/validate/testdata/valid_datadogagent.yaml b/pkg/validate/testdata/valid_datadogagent.yaml
new file mode 100644
index 0000000000..2430922afb
--- /dev/null
+++ b/pkg/validate/testdata/valid_datadogagent.yaml
@@ -0,0 +1,18 @@
+apiVersion: datadoghq.com/v2alpha1
+kind: DatadogAgent
+metadata:
+  name: datadog-demo
+spec:
+  global:
+    clusterName: demo-cluster
+    credentials:
+      apiKey: "0123456789abcdef0123456789abcdef"
+      appKey: "0123456789abcdef0123456789abcdef01234567"
+    commonLabels:
+      team: platform
+      environment: staging
+  features:
+    apm:
+      enabled: true
+    logCollection:
+      enabled: true
diff --git a/pkg/validate/validate.go b/pkg/validate/validate.go
new file mode 100644
index 0000000000..c55130e195
--- /dev/null
+++ b/pkg/validate/validate.go
@@ -0,0 +1,50 @@
+// Unless explicitly stated otherwise all files in this repository are licensed
+// under the Apache License Version 2.0.
+// This product includes software developed at Datadog (https://www.datadoghq.com/).
+// Copyright 2016-present Datadog, Inc.
+
+// Package validate offers a reusable entry point for parsing a DatadogAgent
+// manifest and running the operator's own semantic validation against it,
+// without needing a running cluster or reconcile loop.
+package validate
+
+import (
+	"fmt"
+	"os"
+
+	"sigs.k8s.io/yaml"
+
+	datadoghqv2alpha1 "github.com/DataDog/datadog-operator/api/datadoghq/v2alpha1"
+)
+
+// ParseAndValidateBytes strictly decodes a DatadogAgent YAML/JSON document and
+// runs the operator's semantic validation (the same ValidateDatadogAgent check
+// the reconcile loop performs). Strict decoding rejects unknown/duplicate
+// fields, so structural mistakes surface here rather than being silently
+// dropped. The parsed DatadogAgent is returned so callers can inspect it.
+func ParseAndValidateBytes(data []byte) (*datadoghqv2alpha1.DatadogAgent, error) {
+	dda := &datadoghqv2alpha1.DatadogAgent{}
+	if err := yaml.UnmarshalStrict(data, dda); err != nil {
+		return nil, fmt.Errorf("parsing DatadogAgent: %w", err)
+	}
+
+	if dda.Name == "" {
+		return nil, fmt.Errorf("DatadogAgent has no metadata.name")
+	}
+
+	if err := datadoghqv2alpha1.ValidateDatadogAgent(dda); err != nil {
+		return dda, fmt.Errorf("invalid DatadogAgent %q: %w", dda.Name, err)
+	}
+
+	return dda, nil
+}
+
+// ParseAndValidateFile reads a DatadogAgent manifest from disk and delegates to
+// ParseAndValidateBytes.
+func ParseAndValidateFile(path string) (*datadoghqv2alpha1.DatadogAgent, error) {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return nil, fmt.Errorf("reading %s: %w", path, err)
+	}
+	return ParseAndValidateBytes(data)
+}
diff --git a/pkg/validate/validate_test.go b/pkg/validate/validate_test.go
new file mode 100644
index 0000000000..12a5153350
--- /dev/null
+++ b/pkg/validate/validate_test.go
@@ -0,0 +1,134 @@
+// Unless explicitly stated otherwise all files in this repository are licensed
+// under the Apache License Version 2.0.
+// This product includes software developed at Datadog (https://www.datadoghq.com/).
+// Copyright 2016-present Datadog, Inc.
+
+package validate
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestParseAndValidateBytes(t *testing.T) {
+	tests := []struct {
+		name        string
+		manifest    string
+		wantErr     bool
+		errContains string
+	}{
+		{
+			name: "valid manifest",
+			manifest: `apiVersion: datadoghq.com/v2alpha1
+kind: DatadogAgent
+metadata:
+  name: datadog-demo
+spec:
+  global:
+    credentials:
+      apiKey: key
+      appKey: appkey
+    commonLabels:
+      team: platform
+`,
+			wantErr: false,
+		},
+		{
+			name: "missing name",
+			manifest: `apiVersion: datadoghq.com/v2alpha1
+kind: DatadogAgent
+spec:
+  global:
+    credentials:
+      apiKey: key
+`,
+			wantErr:     true,
+			errContains: "no metadata.name",
+		},
+		{
+			name: "missing credentials fails semantic validation",
+			manifest: `apiVersion: datadoghq.com/v2alpha1
+kind: DatadogAgent
+metadata:
+  name: datadog-demo
+spec:
+  global:
+    clusterName: demo
+`,
+			wantErr:     true,
+			errContains: "credentials not configured",
+		},
+		{
+			name: "reserved commonLabels prefix rejected",
+			manifest: `apiVersion: datadoghq.com/v2alpha1
+kind: DatadogAgent
+metadata:
+  name: datadog-demo
+spec:
+  global:
+    credentials:
+      apiKey: key
+    commonLabels:
+      agent.datadoghq.com/foo: bar
+`,
+			wantErr:     true,
+			errContains: "reserved key",
+		},
+		{
+			name: "unknown field rejected by strict decoding",
+			manifest: `apiVersion: datadoghq.com/v2alpha1
+kind: DatadogAgent
+metadata:
+  name: datadog-demo
+spec:
+  global:
+    credentials:
+      apiKey: key
+    thisFieldDoesNotExist: true
+`,
+			wantErr:     true,
+			errContains: "parsing DatadogAgent",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			dda, err := ParseAndValidateBytes([]byte(tt.manifest))
+			if tt.wantErr {
+				if err == nil {
+					t.Fatalf("expected error, got nil")
+				}
+				if tt.errContains != "" && !strings.Contains(err.Error(), tt.errContains) {
+					t.Fatalf("expected error containing %q, got %q", tt.errContains, err.Error())
+				}
+				return
+			}
+			if err != nil {
+				t.Fatalf("unexpected error: %v", err)
+			}
+			if dda == nil {
+				t.Fatalf("expected non-nil DatadogAgent")
+			}
+			if dda.Name != "datadog-demo" {
+				t.Fatalf("expected name datadog-demo, got %q", dda.Name)
+			}
+		})
+	}
+}
+
+func TestParseAndValidateFile(t *testing.T) {
+	_, err := ParseAndValidateFile("testdata/valid_datadogagent.yaml")
+	if err != nil {
+		t.Fatalf("unexpected error validating demo manifest: %v", err)
+	}
+}
+
+func TestParseAndValidateFile_NotFound(t *testing.T) {
+	_, err := ParseAndValidateFile("testdata/does_not_exist.yaml")
+	if err == nil {
+		t.Fatalf("expected error for missing file")
+	}
+	if !strings.Contains(err.Error(), "reading") {
+		t.Fatalf("expected reading error, got %q", err.Error())
+	}
+}