diff --git a/lib/data/replacements.json b/lib/data/replacements.json
index 9f650fa4773c44..e2f3336b10b2d1 100644
--- a/lib/data/replacements.json
+++ b/lib/data/replacements.json
@@ -1,4 +1,5 @@
 {
+  "$schema": "../../tools/schemas/replacements-schema.json",
   "all": {
     "description": "Apply crowd-sourced package replacement rules.",
     "extends": [
diff --git a/tools/schemas/replacements-schema.json b/tools/schemas/replacements-schema.json
new file mode 100644
index 00000000000000..ca585348c475e3
--- /dev/null
+++ b/tools/schemas/replacements-schema.json
@@ -0,0 +1,61 @@
+{
+  "$schema": "http://json-schema.org/draft-04/schema#",
+  "type": "object",
+  "properties": {
+    "all": {
+      "type": "object",
+      "properties": {
+        "description": { "type": "string" },
+        "extends": {
+          "type": "array",
+          "items": { "type": "string" }
+        },
+        "ignoreDeps": {
+          "type": "array",
+          "items": { "type": "string" }
+        }
+      },
+      "required": ["description", "extends"]
+    }
+  },
+  "patternProperties": {
+    "^[a-zA-Z0-9-]+$": {
+      "type": "object",
+      "properties": {
+        "description": { "type": "string" },
+        "packageRules": {
+          "type": "array",
+          "items": {
+            "type": "object",
+            "properties": {
+              "matchCurrentVersion": { "type": "string" },
+              "matchDatasources": {
+                "type": "array",
+                "items": { "type": "string" }
+              },
+              "matchPackageNames": {
+                "type": "array",
+                "items": { "type": "string" }
+              },
+              "replacementName": { "type": "string" },
+              "replacementVersion": { "type": "string" },
+              "description": { "type": "string" },
+              "replacementNameTemplate": { "type": "string" }
+            },
+            "required": ["matchDatasources", "matchPackageNames"]
+          },
+          "contains": {
+            "type": "object",
+            "oneOf": [
+              { "required": ["replacementName"] },
+              { "required": ["replacementNameTemplate"] }
+            ]
+          },
+          "minItems": 1
+        }
+      },
+      "required": ["description", "packageRules"]
+    }
+  },
+  "additionalProperties": false
+}
diff --git a/tools/schemas/schema.ts b/tools/schemas/schema.ts
index b5361a2472824a..3c3610f71ae6e7 100644
--- a/tools/schemas/schema.ts
+++ b/tools/schemas/schema.ts
@@ -11,4 +11,46 @@ const MonorepoSchema = z.object({
   patternGroups: UrlSchema,
 });
 
-export { MonorepoSchema };
+const PackageRuleSchema = z.object({
+  matchCurrentVersion: z.string().optional(),
+  matchDatasources: z.array(z.string()),
+  matchPackageNames: z.array(z.string()),
+  replacementName: z.string().optional(),
+  replacementVersion: z.string().optional(),
+  description: z.string().optional(),
+  replacementNameTemplate: z.string().optional(),
+});
+
+const RuleSetSchema = z.object({
+  description: z.string(),
+  packageRules: z
+    .array(PackageRuleSchema)
+    .min(1)
+    .refine(
+      (rules) =>
+        rules.some(
+          (rule) =>
+            rule.replacementName !== undefined ||
+            rule.replacementNameTemplate !== undefined,
+        ),
+      {
+        message:
+          'At least one package rule must have either replacementName or replacementNameTemplate',
+      },
+    ),
+});
+
+const AllSchema = z.object({
+  description: z.string(),
+  extends: z.array(z.string()),
+  ignoreDeps: z.array(z.string()).optional(),
+});
+
+const ReplacementsSchema = z
+  .object({
+    $schema: z.string(),
+    all: AllSchema,
+  })
+  .catchall(RuleSetSchema);
+
+export { MonorepoSchema, ReplacementsSchema };