diff --git a/BUILD.bazel b/BUILD.bazel
index 05c9c473d53..41cd2dbffd3 100644
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -33,6 +33,7 @@ mongo_js_library(
     deps = [
         ":node_modules/@eslint/eslintrc",
         ":node_modules/@eslint/js",
+        ":node_modules/eslint-plugin-mocha-no-only",
         ":node_modules/eslint-plugin-mongodb",
         ":node_modules/globals",
         "//src/mongo/shell/debugger/vscode:eslint",
diff --git a/eslint.config.mjs b/eslint.config.mjs
index 4eaf5c941c5..e5dd8bb57bf 100644
--- a/eslint.config.mjs
+++ b/eslint.config.mjs
@@ -1,5 +1,6 @@
 import {FlatCompat} from "@eslint/eslintrc";
 import js from "@eslint/js";
+import mocha_no_only_plugin from "eslint-plugin-mocha-no-only";
 import {default as mongodb_plugin} from "eslint-plugin-mongodb";
 import globals from "globals";
 import path from "node:path";
@@ -318,14 +319,15 @@ export default [
         },
 
         plugins: {
+            mochaNoOnly: mocha_no_only_plugin,
             mongodb: mongodb_plugin,
         },
 
         rules: {
+            "mochaNoOnly/mocha-no-only": 2,
             // TODO SERVER-99571 : enable mongodb/* rules.
             "mongodb/no-print-fn": 0,
             "mongodb/no-printing-tojson": 0,
-
             "no-prototype-builtins": 0,
             "no-useless-escape": 0,
             "no-irregular-whitespace": 0,
diff --git a/jstests/libs/mochalite.js b/jstests/libs/mochalite.js
index 42e3a233b3a..94c31083d5d 100644
--- a/jstests/libs/mochalite.js
+++ b/jstests/libs/mochalite.js
@@ -1,3 +1,4 @@
+/* eslint-disable mochaNoOnly/mocha-no-only */
 /**
  * Simple test framework for running tests in JS files.
  *
diff --git a/jstests/noPassthrough/shell/js/mochalite_only.js b/jstests/noPassthrough/shell/js/mochalite_only.js
index c27461a8671..bb62dd3e495 100644
--- a/jstests/noPassthrough/shell/js/mochalite_only.js
+++ b/jstests/noPassthrough/shell/js/mochalite_only.js
@@ -1,3 +1,4 @@
+/* eslint-disable mochaNoOnly/mocha-no-only -- this file tests the .only() feature of mochalite itself */
 import {after, afterEach, before, beforeEach, describe, it} from "jstests/libs/mochalite.js";
 
 const log = [];
diff --git a/jstests/noPassthrough/shell/js/mochalite_skip.js b/jstests/noPassthrough/shell/js/mochalite_skip.js
index dfcf2e02a6e..a792d2b8229 100644
--- a/jstests/noPassthrough/shell/js/mochalite_skip.js
+++ b/jstests/noPassthrough/shell/js/mochalite_skip.js
@@ -26,7 +26,7 @@ describe("describe", () => {
         beforeEach(die);
         afterEach(die);
         after(die);
-        it.only("test5", die);
+        it.only("test5", die); // eslint-disable-line mochaNoOnly/mocha-no-only
     });
 });
 
diff --git a/jstests/sharding/set_user_write_block_mode.js b/jstests/sharding/set_user_write_block_mode.js
index f66f5a05555..e06410dce71 100644
--- a/jstests/sharding/set_user_write_block_mode.js
+++ b/jstests/sharding/set_user_write_block_mode.js
@@ -22,7 +22,7 @@ import {removeShard} from "jstests/sharding/libs/remove_shard_util.js";
 import {ShardedIndexUtil} from "jstests/sharding/libs/sharded_index_util.js";
 import {after, afterEach, before, beforeEach, describe, it} from "jstests/libs/mochalite.js";
 
-describe.only("setUserWriteBlockMode on replicaset", function () {
+describe("setUserWriteBlockMode on replicaset", function () {
     before(() => {
         this.is_83 = () => {
             const admin = this.rs.getPrimary().getDB("admin");
diff --git a/package.json b/package.json
index 94e8e78cb64..c87877f90ec 100644
--- a/package.json
+++ b/package.json
@@ -7,6 +7,7 @@
     "@eslint/js": "^9",
     "eslint": "9.19.0",
     "eslint-formatter-unix": "^8.40.0",
+    "eslint-plugin-mocha-no-only": "^1.2.0",
     "globals": "14.0.0",
     "prettier": "3.4.2"
   },
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 50070537b90..95b818495a8 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -24,6 +24,9 @@ devDependencies:
   eslint-formatter-unix:
     specifier: ^8.40.0
     version: 8.40.0
+  eslint-plugin-mocha-no-only:
+    specifier: ^1.2.0
+    version: 1.2.0
   globals:
     specifier: 14.0.0
     version: 14.0.0
@@ -245,6 +248,13 @@ packages:
     engines: {node: ^12.22.0 || ^14.17.0 || >=16.0.0}
     dev: true
 
+  /eslint-plugin-mocha-no-only@1.2.0:
+    resolution: {integrity: sha512-sgOilWiikVmYysUvt9q7oUMBYuv/Tka8lQH3766DNxOVqJAKwmP7QqmGYVBiVmqGnn5CDYAo3WWT0F8qw5BDMQ==}
+    engines: {node: '>=0.10.0'}
+    dependencies:
+      requireindex: 1.1.0
+    dev: true
+
   /eslint-scope@8.2.0:
     resolution: {integrity: sha512-PHlWUfG6lvPc3yvP5A4PNyBL1W8fkDUccmI21JUu/+GKZBoH/W5u6usENXUrWFRsyoW5ACUjFGgAFQp5gUlb/A==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
@@ -551,6 +561,11 @@ packages:
     engines: {node: '>=6'}
     dev: true
 
+  /requireindex@1.1.0:
+    resolution: {integrity: sha512-LBnkqsDE7BZKvqylbmn7lTIVdpx4K/QCduRATpO5R+wtPmky/a8pN1bO2D6wXppn1497AJF9mNjqAXr6bdl9jg==}
+    engines: {node: '>=0.10.5'}
+    dev: true
+
   /resolve-from@4.0.0:
     resolution: {integrity: sha512-pb/MYmXstAkysRFx8piNI1tGFNQIFA3vkE3Gq4EuA1dF6gHp/+vgZqsCGJapvy8N3Q+4o7FwvquPJcnZ7RYy4g==}
     engines: {node: '>=4'}