diff --git a/packages/eslint-config/base.js b/packages/eslint-config/base.js
index 6c5ec42..ff301ba 100644
--- a/packages/eslint-config/base.js
+++ b/packages/eslint-config/base.js
@@ -1,5 +1,6 @@
 import js from "@eslint/js";
 import eslintConfigPrettier from "eslint-config-prettier";
+import reactStrictStructure from "eslint-plugin-react-strict-structure";
 import strictEnv from "eslint-plugin-strict-env";
 import turboPlugin from "eslint-plugin-turbo";
 import tseslint from "typescript-eslint";
@@ -23,9 +24,11 @@ export const config = [
   },
   {
     plugins: {
+      "react-strict-structure": reactStrictStructure,
       "strict-env": strictEnv,
     },
     rules: {
+      "react-strict-structure/no-inline-jsx-functions": "error",
       "strict-env/no-process-env": "error",
     },
   },
diff --git a/packages/eslint-config/package.json b/packages/eslint-config/package.json
index 69a0447..f6f2469 100644
--- a/packages/eslint-config/package.json
+++ b/packages/eslint-config/package.json
@@ -18,6 +18,7 @@
     "eslint-plugin-only-warn": "^1.1.0",
     "eslint-plugin-react": "^7.37.5",
     "eslint-plugin-react-hooks": "^5.2.0",
+    "eslint-plugin-react-strict-structure": "workspace:*",
     "eslint-plugin-strict-env": "workspace:*",
     "eslint-plugin-turbo": "^2.5.5",
     "globals": "^15.15.0",
diff --git a/packages/eslint-plugin-react-strict-structure/README.md b/packages/eslint-plugin-react-strict-structure/README.md
new file mode 100644
index 0000000..e4ef595
--- /dev/null
+++ b/packages/eslint-plugin-react-strict-structure/README.md
@@ -0,0 +1,20 @@
+# eslint-plugin-react-strict-structure
+
+A custom ESLint plugin to enforce strict React performance patterns. Specifically, it prevents the definition of inline functions that return JSX inside components.
+
+## Why use this?
+
+Defining a function that returns JSX _inside_ another component (often called a "render helper") is a React anti-pattern.
+
+```javascript
+// ❌ BAD
+function Parent() {
+  // This function is re-created on every render
+  const RenderItem = () => <div>Item</div>;
+
+  // React treats <RenderItem /> as a BRAND NEW component type every time.
+  // Result: It unmounts the old one, mounts the new one.
+  // Side effects: Loss of state, loss of focus, high memory churn.
+  return <RenderItem />;
+}
+```
diff --git a/packages/eslint-plugin-react-strict-structure/index.js b/packages/eslint-plugin-react-strict-structure/index.js
new file mode 100644
index 0000000..fbdee74
--- /dev/null
+++ b/packages/eslint-plugin-react-strict-structure/index.js
@@ -0,0 +1,15 @@
+import { noInlineJsxFunctions } from "./rules/no-inline-jsx-functions.js";
+
+export default {
+  rules: {
+    'no-inline-jsx-functions': noInlineJsxFunctions,
+  },
+  configs: {
+    recommended: {
+      plugins: ['react-strict-structure'],
+      rules: {
+        'react-strict-structure/no-inline-jsx-functions': 'error',
+      },
+    },
+  },
+};
diff --git a/packages/eslint-plugin-react-strict-structure/package.json b/packages/eslint-plugin-react-strict-structure/package.json
new file mode 100644
index 0000000..d2cbfae
--- /dev/null
+++ b/packages/eslint-plugin-react-strict-structure/package.json
@@ -0,0 +1,21 @@
+{
+  "name": "eslint-plugin-react-strict-structure",
+  "version": "0.0.1",
+  "type": "module",
+  "main": "index.js",
+  "scripts": {
+    "test": "node --test src/rules/no-inline-jsx-functions.test.js"
+  },
+  "keywords": [
+    "eslint",
+    "eslint-plugin",
+    "eslint-plugin-react",
+    "eslint-plugin-react-jsx"
+  ],
+  "peerDependencies": {
+    "eslint": ">=9.0.0"
+  },
+  "devDependencies": {
+    "eslint": "^9.39.2"
+  }
+}
diff --git a/packages/eslint-plugin-react-strict-structure/rules/no-inline-jsx-functions.js b/packages/eslint-plugin-react-strict-structure/rules/no-inline-jsx-functions.js
new file mode 100644
index 0000000..133f841
--- /dev/null
+++ b/packages/eslint-plugin-react-strict-structure/rules/no-inline-jsx-functions.js
@@ -0,0 +1,98 @@
+export const noInlineJsxFunctions = {
+  meta: {
+    type: "problem",
+    docs: {
+      description:
+        "Prevent definition of inline functions that return JSX inside components",
+      category: "Best Practices",
+      recommended: true,
+    },
+    schema: [],
+    messages: {
+      noInlineJsx:
+        "Avoid defining functions that return JSX inside components. Move this to a separate component or outside the body.",
+    },
+  },
+  create(context) {
+    return {
+      // Check Function Declarations, Expressions, and Arrow Functions
+      ":function"(node) {
+        if (!parentFunction(parent(node.parent))) {
+          // It's a top-level component, which is fine
+          return;
+        }
+
+        if (isReturnJSX(node.body)) {
+          context.report({
+            node,
+            messageId: "noInlineJsx",
+          });
+        }
+      },
+    };
+  },
+};
+
+function parent(nodeParent) {
+  let parent = nodeParent;
+  while (parent) {
+    if (isFunction(parent)) {
+      return parent;
+    }
+    parent = parent.parent;
+  }
+
+  return parent;
+}
+
+function parentFunction(parent) {
+  while (parent) {
+    if (isFunction(parent)) {
+      return parent;
+    }
+  }
+
+  return null;
+}
+
+function isReturnJSX(nodeBody) {
+  const { body, type } = nodeBody;
+  if (type === "BlockStatement") {
+    // Look for 'return <JSX />' inside the function body
+    for (const { argument, type } of body) {
+      if (type === "ReturnStatement" && isJSX(argument)) {
+        return true;
+      }
+    }
+
+    return false;
+  }
+
+  if (isJSX(nodeBody)) {
+    // Implicit arrow return: () => <div />
+    return true;
+  }
+
+  return false;
+}
+
+function isFunction(node) {
+  if (!node) {
+    return false;
+  }
+
+  return [
+    "FunctionDeclaration",
+    "FunctionExpression",
+    "ArrowFunctionExpression",
+  ].includes(node.type);
+}
+
+function isJSX(node) {
+  if (!node) {
+    return false;
+  }
+
+  const { type } = node;
+  return type === "JSXElement" || type === "JSXFragment";
+}
diff --git a/packages/eslint-plugin-react-strict-structure/rules/no-inline-jsx-functions.test.js b/packages/eslint-plugin-react-strict-structure/rules/no-inline-jsx-functions.test.js
new file mode 100644
index 0000000..5e4ba55
--- /dev/null
+++ b/packages/eslint-plugin-react-strict-structure/rules/no-inline-jsx-functions.test.js
@@ -0,0 +1,45 @@
+import { RuleTester } from "eslint";
+import { noInlineJsxFunctions } from "./no-inline-jsx-functions.js";
+
+new RuleTester({
+  languageOptions: {
+    ecmaVersion: 2020,
+    sourceType: "module",
+    parserOptions: {
+      ecmaFeatures: {
+        jsx: true,
+      },
+    },
+  },
+}).run("no-inline-jsx-functions", noInlineJsxFunctions, {
+  valid: [
+    {
+      code: `function MyComponent() { return <div>Hello</div>; }`,
+    },
+    {
+      code: `const Helper = () => <span>Helper</span>; function MyComponent() { return <Helper />; }`,
+    },
+  ],
+  invalid: [
+    {
+      code: `
+        function MyComponent() {
+          function NestedHelper() {
+            return <div>Bad</div>;
+          }
+          return <NestedHelper />;
+        }
+      `,
+      errors: [{ messageId: "noInlineJsx" }],
+    },
+    {
+      code: `
+        const MyComponent = () => {
+          const renderItem = () => <span>Item</span>; 
+          return <div>{renderItem()}</div>;
+        };
+      `,
+      errors: [{ messageId: "noInlineJsx" }],
+    },
+  ],
+});
\ No newline at end of file
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index ce2cdc3..064782f 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -172,6 +172,9 @@ importers:
       eslint-plugin-react-hooks:
         specifier: ^5.2.0
         version: 5.2.0(eslint@9.32.0(jiti@2.5.1))
+      eslint-plugin-react-strict-structure:
+        specifier: workspace:*
+        version: link:../eslint-plugin-react-strict-structure
       eslint-plugin-strict-env:
         specifier: workspace:*
         version: link:../eslint-plugin-strict-env
@@ -188,6 +191,12 @@ importers:
         specifier: ^8.39.0
         version: 8.39.0(eslint@9.32.0(jiti@2.5.1))(typescript@5.9.2)
 
+  packages/eslint-plugin-react-strict-structure:
+    devDependencies:
+      eslint:
+        specifier: ^9.39.2
+        version: 9.39.2(jiti@2.5.1)
+
   packages/eslint-plugin-strict-env:
     devDependencies:
       eslint:
@@ -293,6 +302,12 @@ packages:
     peerDependencies:
       eslint: ^6.0.0 || ^7.0.0 || >=8.0.0
 
+  '@eslint-community/eslint-utils@4.9.0':
+    resolution: {integrity: sha512-ayVFHdtZ+hsq1t2Dy24wCmGXGe4q9Gu3smhLYALJrr473ZH27MsnSL+LKUlimp4BWJqMDMLmPpx/Q9R3OAlL4g==}
+    engines: {node: ^12.22.0 || ^14.17.0 || >=16.0.0}
+    peerDependencies:
+      eslint: ^6.0.0 || ^7.0.0 || >=8.0.0
+
   '@eslint-community/regexpp@4.12.1':
     resolution: {integrity: sha512-CCZCDJuduB9OUkFkY2IgppNZMi2lBQgD2qzwXkEia16cge2pijY/aXi96CJMquDMn3nJdlPV1A5KrJEXwfLNzQ==}
     engines: {node: ^12.0.0 || ^14.0.0 || >=16.0.0}
@@ -301,14 +316,26 @@ packages:
     resolution: {integrity: sha512-ENIdc4iLu0d93HeYirvKmrzshzofPw6VkZRKQGe9Nv46ZnWUzcF1xV01dcvEg/1wXUR61OmmlSfyeyO7EvjLxQ==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
 
+  '@eslint/config-array@0.21.1':
+    resolution: {integrity: sha512-aw1gNayWpdI/jSYVgzN5pL0cfzU02GT3NBpeT/DXbx1/1x7ZKxFPd9bwrzygx/qiwIQiJ1sw/zD8qY/kRvlGHA==}
+    engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
+
   '@eslint/config-helpers@0.3.0':
     resolution: {integrity: sha512-ViuymvFmcJi04qdZeDc2whTHryouGcDlaxPqarTD0ZE10ISpxGUVZGZDx4w01upyIynL3iu6IXH2bS1NhclQMw==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
 
+  '@eslint/config-helpers@0.4.2':
+    resolution: {integrity: sha512-gBrxN88gOIf3R7ja5K9slwNayVcZgK6SOUORm2uBzTeIEfeVaIhOpCtTox3P6R7o2jLFwLFTLnC7kU/RGcYEgw==}
+    engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
+
   '@eslint/core@0.15.1':
     resolution: {integrity: sha512-bkOp+iumZCCbt1K1CmWf0R9pM5yKpDv+ZXtvSyQpudrI9kuFLp+bM2WOPXImuD/ceQuaa8f5pj93Y7zyECIGNA==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
 
+  '@eslint/core@0.17.0':
+    resolution: {integrity: sha512-yL/sLrpmtDaFEiUj1osRP4TI2MDz1AddJL+jZ7KSqvBuliN4xqYY54IfdN8qD8Toa6g1iloph1fxQNkjOxrrpQ==}
+    engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
+
   '@eslint/eslintrc@3.3.1':
     resolution: {integrity: sha512-gtF186CXhIl1p4pJNGZw8Yc6RlshoePRvE0X91oPGb3vZ8pM3qOS9W9NGPat9LziaBV7XrJWGylNQXkGcnM3IQ==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
@@ -321,14 +348,26 @@ packages:
     resolution: {integrity: sha512-S26Stp4zCy88tH94QbBv3XCuzRQiZ9yXofEILmglYTh/Ug/a9/umqvgFtYBAo3Lp0nsI/5/qH1CCrbdK3AP1Tw==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
 
+  '@eslint/js@9.39.2':
+    resolution: {integrity: sha512-q1mjIoW1VX4IvSocvM/vbTiveKC4k9eLrajNEuSsmjymSDEbpGddtpfOoN7YGAqBK3NG+uqo8ia4PDTt8buCYA==}
+    engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
+
   '@eslint/object-schema@2.1.6':
     resolution: {integrity: sha512-RBMg5FRL0I0gs51M/guSAj5/e14VQ4tpZnQNWwuDT66P14I43ItmPfIZRhO9fUVIPOAQXU47atlywZ/czoqFPA==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
 
+  '@eslint/object-schema@2.1.7':
+    resolution: {integrity: sha512-VtAOaymWVfZcmZbp6E2mympDIHvyjXs/12LqWYjVw6qjrfF+VK+fyG33kChz3nnK+SU5/NeHOqrTEHS8sXO3OA==}
+    engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
+
   '@eslint/plugin-kit@0.3.4':
     resolution: {integrity: sha512-Ul5l+lHEcw3L5+k8POx6r74mxEYKG5kOb6Xpy2gCRW6zweT6TEhAf8vhxGgjhqrd/VO/Dirhsb+1hNpD1ue9hw==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
 
+  '@eslint/plugin-kit@0.4.1':
+    resolution: {integrity: sha512-43/qtrDUokr7LJqoF2c3+RInu/t4zfrpYdoSDfYyhg52rwLV6TnOvdG4fXm7IkSB3wErkcmJS9iEhjVtOSEjjA==}
+    engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
+
   '@humanfs/core@0.19.1':
     resolution: {integrity: sha512-5DyQ4+1JEUzejeK1JGICcideyfUbGixgS9jNgex5nqkW+cY7WZhxBigmieN5Qnw9ZosSNVC9KQKyb+GUaGyKUA==}
     engines: {node: '>=18.18.0'}
@@ -1407,6 +1446,16 @@ packages:
       jiti:
         optional: true
 
+  eslint@9.39.2:
+    resolution: {integrity: sha512-LEyamqS7W5HB3ujJyvi0HQK/dtVINZvd5mAAp9eT5S/ujByGjiZLCzPcHVzuXbpJDJF/cxwHlfceVUDZ2lnSTw==}
+    engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
+    hasBin: true
+    peerDependencies:
+      jiti: '*'
+    peerDependenciesMeta:
+      jiti:
+        optional: true
+
   espree@10.4.0:
     resolution: {integrity: sha512-j6PAQ2uUr79PZhBjP5C5fhl8e39FmRnOjsD5lGnWrFU8i2G776tBK7+nP8KuQUTTyAZUwfQqXAgrVH5MbH9CYQ==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
@@ -2836,6 +2885,11 @@ snapshots:
       eslint: 9.32.0(jiti@2.5.1)
       eslint-visitor-keys: 3.4.3
 
+  '@eslint-community/eslint-utils@4.9.0(eslint@9.39.2(jiti@2.5.1))':
+    dependencies:
+      eslint: 9.39.2(jiti@2.5.1)
+      eslint-visitor-keys: 3.4.3
+
   '@eslint-community/regexpp@4.12.1': {}
 
   '@eslint/config-array@0.21.0':
@@ -2846,12 +2900,28 @@ snapshots:
     transitivePeerDependencies:
       - supports-color
 
+  '@eslint/config-array@0.21.1':
+    dependencies:
+      '@eslint/object-schema': 2.1.7
+      debug: 4.4.1
+      minimatch: 3.1.2
+    transitivePeerDependencies:
+      - supports-color
+
   '@eslint/config-helpers@0.3.0': {}
 
+  '@eslint/config-helpers@0.4.2':
+    dependencies:
+      '@eslint/core': 0.17.0
+
   '@eslint/core@0.15.1':
     dependencies:
       '@types/json-schema': 7.0.15
 
+  '@eslint/core@0.17.0':
+    dependencies:
+      '@types/json-schema': 7.0.15
+
   '@eslint/eslintrc@3.3.1':
     dependencies:
       ajv: 6.12.6
@@ -2870,13 +2940,22 @@ snapshots:
 
   '@eslint/js@9.39.1': {}
 
+  '@eslint/js@9.39.2': {}
+
   '@eslint/object-schema@2.1.6': {}
 
+  '@eslint/object-schema@2.1.7': {}
+
   '@eslint/plugin-kit@0.3.4':
     dependencies:
       '@eslint/core': 0.15.1
       levn: 0.4.1
 
+  '@eslint/plugin-kit@0.4.1':
+    dependencies:
+      '@eslint/core': 0.17.0
+      levn: 0.4.1
+
   '@humanfs/core@0.19.1': {}
 
   '@humanfs/node@0.16.6':
@@ -4045,6 +4124,47 @@ snapshots:
     transitivePeerDependencies:
       - supports-color
 
+  eslint@9.39.2(jiti@2.5.1):
+    dependencies:
+      '@eslint-community/eslint-utils': 4.9.0(eslint@9.39.2(jiti@2.5.1))
+      '@eslint-community/regexpp': 4.12.1
+      '@eslint/config-array': 0.21.1
+      '@eslint/config-helpers': 0.4.2
+      '@eslint/core': 0.17.0
+      '@eslint/eslintrc': 3.3.1
+      '@eslint/js': 9.39.2
+      '@eslint/plugin-kit': 0.4.1
+      '@humanfs/node': 0.16.6
+      '@humanwhocodes/module-importer': 1.0.1
+      '@humanwhocodes/retry': 0.4.3
+      '@types/estree': 1.0.8
+      ajv: 6.12.6
+      chalk: 4.1.2
+      cross-spawn: 7.0.6
+      debug: 4.4.1
+      escape-string-regexp: 4.0.0
+      eslint-scope: 8.4.0
+      eslint-visitor-keys: 4.2.1
+      espree: 10.4.0
+      esquery: 1.6.0
+      esutils: 2.0.3
+      fast-deep-equal: 3.1.3
+      file-entry-cache: 8.0.0
+      find-up: 5.0.0
+      glob-parent: 6.0.2
+      ignore: 5.3.2
+      imurmurhash: 0.1.4
+      is-glob: 4.0.3
+      json-stable-stringify-without-jsonify: 1.0.1
+      lodash.merge: 4.6.2
+      minimatch: 3.1.2
+      natural-compare: 1.4.0
+      optionator: 0.9.4
+    optionalDependencies:
+      jiti: 2.5.1
+    transitivePeerDependencies:
+      - supports-color
+
   espree@10.4.0:
     dependencies:
       acorn: 8.15.0