diff --git a/lib/helpers/model/castBulkWrite.js b/lib/helpers/model/castBulkWrite.js
index 56ee9548062..49b0ded06df 100644
--- a/lib/helpers/model/castBulkWrite.js
+++ b/lib/helpers/model/castBulkWrite.js
@@ -28,7 +28,7 @@ module.exports = function castBulkWrite(originalModel, op, options) {
       const model = decideModelByObject(originalModel, op['insertOne']['document']);
 
       const doc = new model(op['insertOne']['document']);
-      if (model.schema.options.timestamps && options.timestamps !== false) {
+      if (model.schema.options.timestamps && (op['insertOne'].timestamps ?? options.timestamps ?? true)) {
         doc.initializeTimestamps();
       }
       if (options.session != null) {
@@ -70,7 +70,8 @@ module.exports = function castBulkWrite(originalModel, op, options) {
           const createdAt = model.schema.$timestamps.createdAt;
           const updatedAt = model.schema.$timestamps.updatedAt;
           applyTimestampsToUpdate(now, createdAt, updatedAt, op['updateOne']['update'], {
-            timestamps: op['updateOne'].timestamps
+            timestamps: op['updateOne'].timestamps,
+            overwriteImmutable: op['updateOne'].overwriteImmutable
           });
         }
 
@@ -140,7 +141,8 @@ module.exports = function castBulkWrite(originalModel, op, options) {
           const createdAt = model.schema.$timestamps.createdAt;
           const updatedAt = model.schema.$timestamps.updatedAt;
           applyTimestampsToUpdate(now, createdAt, updatedAt, op['updateMany']['update'], {
-            timestamps: op['updateMany'].timestamps
+            timestamps: op['updateMany'].timestamps,
+            overwriteImmutable: op['updateMany'].overwriteImmutable
           });
         }
         if (op['updateMany'].timestamps !== false) {
@@ -190,7 +192,7 @@ module.exports = function castBulkWrite(originalModel, op, options) {
 
       // set `skipId`, otherwise we get "_id field cannot be changed"
       const doc = new model(op['replaceOne']['replacement'], strict, true);
-      if (model.schema.options.timestamps) {
+      if (model.schema.options.timestamps && (op['replaceOne'].timestamps ?? options.timestamps ?? true)) {
         doc.initializeTimestamps();
       }
       if (options.session != null) {
@@ -279,3 +281,4 @@ function decideModelByObject(model, object) {
   }
   return model;
 }
+
diff --git a/lib/helpers/update/applyTimestampsToUpdate.js b/lib/helpers/update/applyTimestampsToUpdate.js
index b48febafb69..ae83b403117 100644
--- a/lib/helpers/update/applyTimestampsToUpdate.js
+++ b/lib/helpers/update/applyTimestampsToUpdate.js
@@ -81,33 +81,46 @@ function applyTimestampsToUpdate(now, createdAt, updatedAt, currentUpdate, optio
   }
 
   if (!skipCreatedAt && createdAt) {
-    if (currentUpdate[createdAt]) {
-      delete currentUpdate[createdAt];
-    }
-    if (currentUpdate.$set && currentUpdate.$set[createdAt]) {
-      delete currentUpdate.$set[createdAt];
-    }
-    let timestampSet = false;
-    if (createdAt.indexOf('.') !== -1) {
-      const pieces = createdAt.split('.');
-      for (let i = 1; i < pieces.length; ++i) {
-        const remnant = pieces.slice(-i).join('.');
-        const start = pieces.slice(0, -i).join('.');
-        if (currentUpdate[start] != null) {
-          currentUpdate[start][remnant] = now;
-          timestampSet = true;
-          break;
-        } else if (currentUpdate.$set && currentUpdate.$set[start]) {
-          currentUpdate.$set[start][remnant] = now;
-          timestampSet = true;
-          break;
+    const overwriteImmutable = get(options, 'overwriteImmutable', false);
+    const hasUserCreatedAt = currentUpdate[createdAt] != null || currentUpdate?.$set[createdAt] != null;
+
+    // If overwriteImmutable is true and user provided createdAt, keep their value
+    if (overwriteImmutable && hasUserCreatedAt) {
+      // Move createdAt from top-level to $set if needed
+      if (currentUpdate[createdAt] != null) {
+        updates.$set[createdAt] = currentUpdate[createdAt];
+        delete currentUpdate[createdAt];
+      }
+      // User's value is already in $set, nothing more to do
+    } else {
+      if (currentUpdate[createdAt]) {
+        delete currentUpdate[createdAt];
+      }
+      if (currentUpdate.$set && currentUpdate.$set[createdAt]) {
+        delete currentUpdate.$set[createdAt];
+      }
+      let timestampSet = false;
+      if (createdAt.indexOf('.') !== -1) {
+        const pieces = createdAt.split('.');
+        for (let i = 1; i < pieces.length; ++i) {
+          const remnant = pieces.slice(-i).join('.');
+          const start = pieces.slice(0, -i).join('.');
+          if (currentUpdate[start] != null) {
+            currentUpdate[start][remnant] = now;
+            timestampSet = true;
+            break;
+          } else if (currentUpdate.$set && currentUpdate.$set[start]) {
+            currentUpdate.$set[start][remnant] = now;
+            timestampSet = true;
+            break;
+          }
         }
       }
-    }
 
-    if (!timestampSet) {
-      updates.$setOnInsert = updates.$setOnInsert || {};
-      updates.$setOnInsert[createdAt] = now;
+      if (!timestampSet) {
+        updates.$setOnInsert = updates.$setOnInsert || {};
+        updates.$setOnInsert[createdAt] = now;
+      }
     }
   }
 
diff --git a/test/model.test.js b/test/model.test.js
index 04516afa3be..d660960a154 100644
--- a/test/model.test.js
+++ b/test/model.test.js
@@ -5926,6 +5926,52 @@ describe('Model', function() {
 
   });
 
+  it('bulkWrite can disable timestamps with insertOne and replaceOne (gh-15782)', async function() {
+    const userSchema = new Schema({
+      name: String
+    }, { timestamps: true });
+
+    const User = db.model('User', userSchema);
+
+    const user = await User.create({ name: 'Hafez' });
+
+    await User.bulkWrite([
+      { insertOne: { document: { name: 'insertOne-test' }, timestamps: false } },
+      { replaceOne: { filter: { _id: user._id }, replacement: { name: 'replaceOne-test' }, timestamps: false } }
+    ]);
+
+    const insertedDoc = await User.findOne({ name: 'insertOne-test' });
+    assert.strictEqual(insertedDoc.createdAt, undefined);
+    assert.strictEqual(insertedDoc.updatedAt, undefined);
+
+    const replacedDoc = await User.findOne({ name: 'replaceOne-test' });
+    assert.strictEqual(replacedDoc.createdAt, undefined);
+    assert.strictEqual(replacedDoc.updatedAt, undefined);
+  });
+
+  it('bulkWrite insertOne and replaceOne respect per-op timestamps: true when global is false (gh-15782)', async function() {
+    const userSchema = new Schema({
+      name: String
+    }, { timestamps: true });
+
+    const User = db.model('User', userSchema);
+
+    const user = await User.create({ name: 'Hafez' });
+
+    await User.bulkWrite([
+      { insertOne: { document: { name: 'insertOne-test' }, timestamps: true } },
+      { replaceOne: { filter: { _id: user._id }, replacement: { name: 'replaceOne-test' }, timestamps: true } }
+    ], { timestamps: false });
+
+    const insertedDoc = await User.findOne({ name: 'insertOne-test' });
+    assert.ok(insertedDoc.createdAt instanceof Date);
+    assert.ok(insertedDoc.updatedAt instanceof Date);
+
+    const replacedDoc = await User.findOne({ name: 'replaceOne-test' });
+    assert.ok(replacedDoc.createdAt instanceof Date);
+    assert.ok(replacedDoc.updatedAt instanceof Date);
+  });
+
   it('bulkwrite should not change updatedAt on subdocs when timestamps set to false (gh-13611)', async function() {
 
     const postSchema = new Schema({
diff --git a/test/model.updateOne.test.js b/test/model.updateOne.test.js
index 5e5954c6c44..5a3ab96ff3a 100644
--- a/test/model.updateOne.test.js
+++ b/test/model.updateOne.test.js
@@ -2707,34 +2707,136 @@ describe('model: updateOne: ', function() {
     assert.equal(doc.age, 20);
   });
 
-  it('overwriting immutable createdAt with bulkWrite (gh-15781)', async function() {
-    const start = new Date().valueOf();
-    const schema = Schema({
-      createdAt: {
-        type: mongoose.Schema.Types.Date,
-        immutable: true
-      },
-      name: String
-    }, { timestamps: true });
+  describe('bulkWrite overwriteImmutable option (gh-15781)', function() {
+    it('updateOne can update immutable field with overwriteImmutable: true', async function() {
+      // Arrange
+      const { User } = createTestContext();
+      const user = await User.create({ name: 'John', ssn: '123-45-6789' });
+      const customCreatedAt = new Date('2020-01-01');
+
+      // Act
+      await User.bulkWrite([{
+        updateOne: {
+          filter: { _id: user._id },
+          update: { createdAt: customCreatedAt, ssn: '999-99-9999' },
+          overwriteImmutable: true
+        }
+      }]);
+
+      // Assert
+      const updatedUser = await User.findById(user._id);
+      assert.strictEqual(updatedUser.ssn, '999-99-9999');
+      assert.strictEqual(updatedUser.createdAt.valueOf(), customCreatedAt.valueOf());
+    });
+
+    it('updateMany can update immutable field with overwriteImmutable: true', async function() {
+      // Arrange
+      const { User } = createTestContext();
+      const user = await User.create({ name: 'Alice', ssn: '111-11-1111' });
+      const customCreatedAt = new Date('2020-01-01');
+
+      // Act
+      await User.bulkWrite([{
+        updateMany: {
+          filter: { _id: user._id },
+          update: { createdAt: customCreatedAt, ssn: '000-00-0000' },
+          overwriteImmutable: true
+        }
+      }]);
 
-    const Model = db.model('Test', schema);
+      // Assert
+      const updatedUser = await User.findById(user._id);
+      assert.strictEqual(updatedUser.ssn, '000-00-0000');
+      assert.strictEqual(updatedUser.createdAt.valueOf(), customCreatedAt.valueOf());
+    });
 
-    await Model.create({ name: 'gh-15781' });
-    let doc = await Model.collection.findOne({ name: 'gh-15781' });
-    assert.ok(doc.createdAt.valueOf() >= start);
+    for (const timestamps of [true, false, null, undefined]) {
+      it(`overwriting immutable createdAt with bulkWrite (gh-15781) when \`timestamps\` is \`${timestamps}\``, async function() {
+        // Arrange
+        const schema = Schema({ name: String }, { timestamps: true });
 
-    const createdAt = new Date('2011-06-01');
-    assert.ok(createdAt.valueOf() < start.valueOf());
-    await Model.bulkWrite([{
-      updateOne: {
-        filter: { _id: doc._id },
-        update: { name: 'gh-15781 update', createdAt },
-        overwriteImmutable: true,
-        timestamps: false
-      }
-    }]);
-    doc = await Model.collection.findOne({ name: 'gh-15781 update' });
-    assert.equal(doc.createdAt.valueOf(), createdAt.valueOf());
+        const Model = db.model('Test', schema);
+
+        const doc1 = await Model.create({ name: 'gh-15781-1' });
+        const doc2 = await Model.create({ name: 'gh-15781-2' });
+
+        // Act
+        const createdAt = new Date('2011-06-01');
+
+        await Model.bulkWrite([
+          {
+            updateOne: {
+              filter: { _id: doc1._id },
+              update: { createdAt },
+              overwriteImmutable: true,
+              timestamps
+            }
+          },
+          {
+            updateMany: {
+              filter: { _id: doc2._id },
+              update: { createdAt },
+              overwriteImmutable: true,
+              timestamps
+            }
+          }
+        ]);
+
+        // Assert
+        const updatesDocs = await Model.find({ _id: { $in: [doc1._id, doc2._id] } });
+
+        assert.equal(updatesDocs[0].createdAt.valueOf(), createdAt.valueOf());
+        assert.equal(updatesDocs[1].createdAt.valueOf(), createdAt.valueOf());
+      });
+    }
+
+    it('can not update immutable fields without overwriteImmutable: true', async function() {
+      // Arrange
+      const { User } = createTestContext();
+      const users = await User.create([
+        { name: 'Bob', ssn: '222-22-2222' },
+        { name: 'Eve', ssn: '333-33-3333' }
+      ]);
+      const newCreatedAt = new Date('2020-01-01');
+
+      // Act
+      await User.bulkWrite([
+        {
+          updateOne: {
+            filter: { _id: users[0]._id },
+            update: { ssn: '888-88-8888', createdAt: newCreatedAt }
+          }
+
+        },
+        {
+          updateMany: {
+            filter: { _id: users[1]._id },
+            update: { ssn: '777-77-7777', createdAt: newCreatedAt }
+          }
+        }
+      ]);
+
+
+      // Assert
+      const [updatedUser1, updatedUser2] = await Promise.all([
+        User.findById(users[0]._id),
+        User.findById(users[1]._id)
+      ]);
+      assert.strictEqual(updatedUser1.ssn, '222-22-2222');
+      assert.notStrictEqual(updatedUser1.createdAt.valueOf(), newCreatedAt.valueOf());
+
+      assert.strictEqual(updatedUser2.ssn, '333-33-3333');
+      assert.notStrictEqual(updatedUser2.createdAt.valueOf(), newCreatedAt.valueOf());
+    });
+
+    function createTestContext() {
+      const userSchema = new Schema({
+        name: String,
+        ssn: { type: String, immutable: true }
+      }, { timestamps: true });
+      const User = db.model('User', userSchema);
+      return { User };
+    }
   });
 
   it('updates buffers with `runValidators` successfully (gh-8580)', async function() {
diff --git a/test/types/models.test.ts b/test/types/models.test.ts
index 0e00f16fc74..08fc0824b9b 100644
--- a/test/types/models.test.ts
+++ b/test/types/models.test.ts
@@ -13,11 +13,13 @@ import mongoose, {
   Query,
   UpdateWriteOpResult,
   AggregateOptions,
-  StringSchemaDefinition
+  StringSchemaDefinition,
+  UpdateOneModel,
+  UpdateManyModel
 } from 'mongoose';
 import { expectAssignable, expectError, expectType } from 'tsd';
 import { AutoTypedSchemaType, autoTypedSchema } from './schema.test';
-import { UpdateOneModel, ChangeStreamInsertDocument, ObjectId } from 'mongodb';
+import { UpdateOneModel as MongoUpdateOneModel, ChangeStreamInsertDocument, ObjectId } from 'mongodb';
 
 function rawDocSyntax(): void {
   interface ITest {
@@ -415,7 +417,7 @@ function gh11911() {
   const Animal = model<IAnimal>('Animal', animalSchema);
 
   const changes: UpdateQuery<IAnimal> = {};
-  expectAssignable<UpdateOneModel>({
+  expectAssignable<MongoUpdateOneModel>({
     filter: {},
     update: changes
   });
@@ -766,3 +768,36 @@ async function gh14003() {
   await TestModel.validate({ name: 'foo' }, ['name']);
   await TestModel.validate({ name: 'foo' }, { pathsToSkip: ['name'] });
 }
+
+async function gh15781() {
+  const userSchema = new Schema({
+    createdAt: { type: Date, immutable: true },
+    name: String
+  }, { timestamps: true });
+
+  const User = model('User', userSchema);
+
+  await User.bulkWrite([
+    {
+      updateOne: {
+        filter: { name: 'John' },
+        update: { createdAt: new Date() },
+        overwriteImmutable: true,
+        timestamps: false
+      }
+    },
+    {
+      updateMany: {
+        filter: { name: 'Jane' },
+        update: { createdAt: new Date() },
+        overwriteImmutable: true,
+        timestamps: false
+      }
+    }
+  ]);
+
+  expectType<boolean | undefined>({} as UpdateOneModel['timestamps']);
+  expectType<boolean | undefined>({} as UpdateOneModel['overwriteImmutable']);
+  expectType<boolean | undefined>({} as UpdateManyModel['timestamps']);
+  expectType<boolean | undefined>({} as UpdateManyModel['overwriteImmutable']);
+}
diff --git a/types/models.d.ts b/types/models.d.ts
index 7cb082bc372..90e7e1456e7 100644
--- a/types/models.d.ts
+++ b/types/models.d.ts
@@ -142,6 +142,46 @@ declare module 'mongoose' {
 
   interface RemoveOptions extends SessionOption, Omit<mongodb.DeleteOptions, 'session'> {}
 
+  interface MongooseBulkWritePerOperationOptions {
+    /** Skip validation for this operation. */
+    skipValidation?: boolean;
+    /** When false, do not add timestamps. When true, overrides the `timestamps` option set in the `bulkWrite` options. */
+    timestamps?: boolean;
+  }
+
+  interface MongooseBulkUpdatePerOperationOptions extends MongooseBulkWritePerOperationOptions {
+    /** When true, allows updating fields that are marked as `immutable` in the schema. */
+    overwriteImmutable?: boolean;
+    /** When false, do not set default values on insert. */
+    setDefaultsOnInsert?: boolean;
+  }
+
+  export type InsertOneModel<TSchema extends mongodb.Document = mongodb.Document> =
+    mongodb.InsertOneModel<TSchema> & MongooseBulkWritePerOperationOptions;
+
+  export type ReplaceOneModel<TSchema extends mongodb.Document = mongodb.Document> =
+    mongodb.ReplaceOneModel<TSchema> & MongooseBulkWritePerOperationOptions;
+
+  export type UpdateOneModel<TSchema extends mongodb.Document = mongodb.Document> =
+    mongodb.UpdateOneModel<TSchema> & MongooseBulkUpdatePerOperationOptions;
+
+  export type UpdateManyModel<TSchema extends mongodb.Document = mongodb.Document> =
+    mongodb.UpdateManyModel<TSchema> & MongooseBulkUpdatePerOperationOptions;
+
+  export type DeleteOneModel<TSchema extends mongodb.Document = mongodb.Document> =
+    mongodb.DeleteOneModel<TSchema>;
+
+  export type DeleteManyModel<TSchema extends mongodb.Document = mongodb.Document> =
+    mongodb.DeleteManyModel<TSchema>;
+
+  export type AnyBulkWriteOperation<TSchema extends mongodb.Document = mongodb.Document> =
+    | { insertOne: InsertOneModel<TSchema> }
+    | { replaceOne: ReplaceOneModel<TSchema> }
+    | { updateOne: UpdateOneModel<TSchema> }
+    | { updateMany: UpdateManyModel<TSchema> }
+    | { deleteOne: DeleteOneModel<TSchema> }
+    | { deleteMany: DeleteManyModel<TSchema> };
+
   const Model: Model<any>;
 
   /**
@@ -185,11 +225,11 @@ declare module 'mongoose' {
      * round trip to the MongoDB server.
      */
     bulkWrite<DocContents = TRawDocType>(
-      writes: Array<mongodb.AnyBulkWriteOperation<DocContents extends Document ? any : (DocContents extends {} ? DocContents : any)>>,
+      writes: Array<AnyBulkWriteOperation<DocContents extends Document ? any : (DocContents extends {} ? DocContents : any)>>,
       options: mongodb.BulkWriteOptions & MongooseBulkWriteOptions & { ordered: false }
     ): Promise<mongodb.BulkWriteResult & { mongoose?: { validationErrors: Error[] } }>;
     bulkWrite<DocContents = TRawDocType>(
-      writes: Array<mongodb.AnyBulkWriteOperation<DocContents extends Document ? any : (DocContents extends {} ? DocContents : any)>>,
+      writes: Array<AnyBulkWriteOperation<DocContents extends Document ? any : (DocContents extends {} ? DocContents : any)>>,
       options?: mongodb.BulkWriteOptions & MongooseBulkWriteOptions
     ): Promise<mongodb.BulkWriteResult>;