diff --git a/packages/backend/src/db/migrations/20231013094544_convert_user_emails_to_lowercase.ts b/packages/backend/src/db/migrations/20231013094544_convert_user_emails_to_lowercase.ts
new file mode 100644
index 00000000..623bfc75
--- /dev/null
+++ b/packages/backend/src/db/migrations/20231013094544_convert_user_emails_to_lowercase.ts
@@ -0,0 +1,13 @@
+import { Knex } from 'knex';
+
+export async function up(knex: Knex): Promise<void> {
+  await knex('users')
+    .whereRaw('email != LOWER(email)')
+    .update({
+      email: knex.raw('LOWER(email)'),
+    });
+}
+
+export async function down(): Promise<void> {
+  // void
+}
diff --git a/packages/backend/src/graphql/mutations/create-user.ee.ts b/packages/backend/src/graphql/mutations/create-user.ee.ts
index 887bdc89..956be348 100644
--- a/packages/backend/src/graphql/mutations/create-user.ee.ts
+++ b/packages/backend/src/graphql/mutations/create-user.ee.ts
@@ -13,12 +13,18 @@ type Params = {
   };
 };
 
-const createUser = async (_parent: unknown, params: Params, context: Context) => {
+const createUser = async (
+  _parent: unknown,
+  params: Params,
+  context: Context
+) => {
   context.currentUser.can('create', 'User');
 
   const { fullName, email, password } = params.input;
 
-  const existingUser = await User.query().findOne({ email });
+  const existingUser = await User.query().findOne({
+    email: email.toLowerCase(),
+  });
 
   if (existingUser) {
     throw new Error('User already exists!');
diff --git a/packages/backend/src/graphql/mutations/forgot-password.ee.ts b/packages/backend/src/graphql/mutations/forgot-password.ee.ts
index 5e28a429..e40a32d9 100644
--- a/packages/backend/src/graphql/mutations/forgot-password.ee.ts
+++ b/packages/backend/src/graphql/mutations/forgot-password.ee.ts
@@ -15,7 +15,7 @@ type Params = {
 const forgotPassword = async (_parent: unknown, params: Params) => {
   const { email } = params.input;
 
-  const user = await User.query().findOne({ email });
+  const user = await User.query().findOne({ email: email.toLowerCase() });
 
   if (!user) {
     throw new Error('Email address not found!');
diff --git a/packages/backend/src/graphql/mutations/register-user.ee.ts b/packages/backend/src/graphql/mutations/register-user.ee.ts
index 0a7ede07..ba0651b4 100644
--- a/packages/backend/src/graphql/mutations/register-user.ee.ts
+++ b/packages/backend/src/graphql/mutations/register-user.ee.ts
@@ -12,7 +12,9 @@ type Params = {
 const registerUser = async (_parent: unknown, params: Params) => {
   const { fullName, email, password } = params.input;
 
-  const existingUser = await User.query().findOne({ email });
+  const existingUser = await User.query().findOne({
+    email: email.toLowerCase(),
+  });
 
   if (existingUser) {
     throw new Error('User already exists!');
diff --git a/packages/backend/src/models/user.ts b/packages/backend/src/models/user.ts
index fe58670c..20060458 100644
--- a/packages/backend/src/models/user.ts
+++ b/packages/backend/src/models/user.ts
@@ -263,6 +263,8 @@ class User extends Base {
 
   async $beforeInsert(queryContext: QueryContext) {
     await super.$beforeInsert(queryContext);
+
+    this.email = this.email.toLowerCase();
     await this.generateHash();
 
     if (appConfig.isCloud) {
@@ -273,6 +275,7 @@ class User extends Base {
   async $beforeUpdate(opt: ModelOptions, queryContext: QueryContext) {
     await super.$beforeUpdate(opt, queryContext);
 
+    this.email = this.email.toLowerCase();
     await this.generateHash();
   }