diff --git a/lib/config/presets/internal/replacements.ts b/lib/config/presets/internal/replacements.ts
index 80b6d569c564c2357f45a07be2127fa11f82f7d2..b2b91debd983317afda927665334e1b6b04b15e5 100644
--- a/lib/config/presets/internal/replacements.ts
+++ b/lib/config/presets/internal/replacements.ts
@@ -1,10 +1,12 @@
-import replacementGroups from '../../../data/replacements.json';
+import replacementGroupsJson from '../../../data/replacements.json';
 import type { Preset } from '../types';
 import type { PresetTemplate, Replacement } from './auto-generate-replacements';
 import { addPresets } from './auto-generate-replacements';
 
+const { $schema, ...replacementPresets } = replacementGroupsJson;
+
 /* eslint sort-keys: ["error", "asc", {"caseSensitive": false, "natural": true}] */
-export const presets: Record<string, Preset> = replacementGroups;
+export const presets: Record<string, Preset> = replacementPresets;
 
 const muiReplacement: Replacement[] = [
   [['@material-ui/codemod'], '@mui/codemod'],
diff --git a/lib/data/replacements.json b/lib/data/replacements.json
index cc7c0819e30c90fbd84ffe3cefda9349308e1dbf..021304c082de8d321357bfe202c76ed8c2833639 100644
--- a/lib/data/replacements.json
+++ b/lib/data/replacements.json
@@ -1,4 +1,5 @@
 {
+  "$schema": "../../tools/schemas/replacements-schema.json",
   "all": {
     "description": "Apply crowd-sourced package replacement rules.",
     "extends": [
diff --git a/tools/schemas/monorepo-schema.json b/tools/schemas/monorepo-schema.json
index 6bc1d6e7a9fabda3d435bb315a8a2e3898276511..7effc4dce2c72f2b08b9e0a371748193482c89cf 100644
--- a/tools/schemas/monorepo-schema.json
+++ b/tools/schemas/monorepo-schema.json
@@ -1,5 +1,5 @@
 {
-  "$schema": "http://json-schema.org/draft-04/schema#",
+  "$schema": "https://json-schema.org/draft-04/schema#",
   "type": "object",
   "properties": {
     "repoGroups": {
diff --git a/tools/schemas/replacements-schema.json b/tools/schemas/replacements-schema.json
new file mode 100644
index 0000000000000000000000000000000000000000..7634f93c9e03ba9ffbbce6ab7f5870f646d73950
--- /dev/null
+++ b/tools/schemas/replacements-schema.json
@@ -0,0 +1,61 @@
+{
+  "$schema": "https://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 b5361a2472824ae41f565f1949d695a0d743beb0..8609e3582e81dc5181dcf762a937b0966c16f04c 100644
--- a/tools/schemas/schema.ts
+++ b/tools/schemas/schema.ts
@@ -5,10 +5,50 @@ const UrlSchema = z.record(
   z.union([z.string(), z.array(z.string())]),
 );
 
-const MonorepoSchema = z.object({
+export const MonorepoSchema = z.object({
   repoGroups: UrlSchema,
   orgGroups: UrlSchema,
   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 use either the replacementName config option, or the replacementNameTemplate config option',
+      },
+    ),
+});
+
+const AllSchema = z.object({
+  description: z.string(),
+  extends: z.array(z.string()),
+  ignoreDeps: z.array(z.string()).optional(),
+});
+
+export const ReplacementsSchema = z
+  .object({
+    $schema: z.string(),
+    all: AllSchema,
+  })
+  .catchall(RuleSetSchema);