diff --git a/frappe/commands/site.py b/frappe/commands/site.py
index 36bb71d7a1..0bbd8c988f 100644
--- a/frappe/commands/site.py
+++ b/frappe/commands/site.py
@@ -53,6 +53,7 @@ from frappe.exceptions import SiteNotSpecifiedError
 	default=True,
 	help="Create user and database in mariadb/postgres; only bootstrap if false",
 )
+@click.option("--db-user", help="Database user if you already have one")
 def new_site(
 	site,
 	db_root_username=None,
diff --git a/frappe/database/db_manager.py b/frappe/database/db_manager.py
index 4e1404084e..7904d5322b 100644
--- a/frappe/database/db_manager.py
+++ b/frappe/database/db_manager.py
@@ -18,6 +18,20 @@ class DbManager:
 		password_predicate = f" IDENTIFIED BY '{password}'" if password else ""
 		self.db.sql(f"CREATE USER '{user}'@'{host}'{password_predicate}")
 
+	def does_user_exist(self, username: str, host: str | None = None) -> bool:
+		return (
+			self.db.sql(
+				f"SELECT EXISTS(SELECT 1 FROM mysql.user WHERE user = '{username}' and "
+				f"host = '{host or self.get_current_host()}')"
+			)[0][0]
+			== 1
+		)
+
+	def set_user_password(self, username: str, password: str, host: str | None = None) -> None:
+		self.db.sql(
+			f"SET PASSWORD FOR '{username}'@'{host or self.get_current_host()}' = PASSWORD('{password}')"
+		)
+
 	def delete_user(self, target, host=None):
 		host = host or self.get_current_host()
 		self.db.sql(f"DROP USER IF EXISTS '{target}'@'{host}'")
diff --git a/frappe/database/mariadb/setup_db.py b/frappe/database/mariadb/setup_db.py
index 9760ec1e66..c1449f2456 100644
--- a/frappe/database/mariadb/setup_db.py
+++ b/frappe/database/mariadb/setup_db.py
@@ -34,16 +34,21 @@ def setup_database(force, verbose, no_mariadb_socket=False):
 	if no_mariadb_socket:
 		dbman_kwargs["host"] = "%"
 
+	if dbman.does_user_exist(db_user):
+		print("User exists", db_user)
+		dbman.set_user_password(db_user, frappe.conf.db_password, **dbman_kwargs)
+		if verbose:
+			print("Re-used existing user %s" % db_user)
+	else:
+		dbman.create_user(db_user, frappe.conf.db_password, **dbman_kwargs)
+		if verbose:
+			print("Created user %s" % db_user)
+
 	if force or (db_name not in dbman.get_database_list()):
-		dbman.delete_user(db_user, **dbman_kwargs)
 		dbman.drop_database(db_name)
 	else:
 		raise Exception(f"Database {db_name} already exists")
 
-	dbman.create_user(db_user, frappe.conf.db_password, **dbman_kwargs)
-	if verbose:
-		print("Created user %s" % db_user)
-
 	dbman.create_database(db_name)
 	if verbose:
 		print("Created database %s" % db_name)
diff --git a/frappe/database/postgres/setup_db.py b/frappe/database/postgres/setup_db.py
index 264de90c95..aeb105a24f 100644
--- a/frappe/database/postgres/setup_db.py
+++ b/frappe/database/postgres/setup_db.py
@@ -11,15 +11,21 @@ def setup_database():
 	root_conn.commit()
 	root_conn.sql("end")
 	root_conn.sql(f"DROP DATABASE IF EXISTS `{frappe.conf.db_name}`")
-	root_conn.sql(f"DROP USER IF EXISTS {frappe.conf.db_name}")
+
+	# If user exists, just update password
+	if root_conn.sql(f"SELECT 1 FROM pg_roles WHERE rolname='{frappe.conf.db_user}'"):
+		root_conn.sql(f"ALTER USER {frappe.conf.db_user} WITH PASSWORD '{frappe.conf.db_password}'")
+	else:
+		root_conn.sql(f"CREATE USER {frappe.conf.db_user} WITH PASSWORD '{frappe.conf.db_password}'")
 	root_conn.sql(f"CREATE DATABASE `{frappe.conf.db_name}`")
-	root_conn.sql(f"CREATE user {frappe.conf.db_name} password '{frappe.conf.db_password}'")
-	root_conn.sql("GRANT ALL PRIVILEGES ON DATABASE `{0}` TO {0}".format(frappe.conf.db_name))
+	root_conn.sql(
+		f"GRANT ALL PRIVILEGES ON DATABASE `{frappe.conf.db_name}` TO {frappe.conf.db_user}"
+	)
 	if psql_version := root_conn.sql("SELECT VERSION()", as_dict=True):
 		version_string = psql_version[0].get("version") or "PostgreSQL 14"
 		major_version = cint(re.split(r"[\w\.]", version_string)[1])
 		if major_version > 15:
-			root_conn.sql("ALTER DATABASE `{0}` OWNER TO {0}".format(frappe.conf.db_name))
+			root_conn.sql(f"ALTER DATABASE `{frappe.conf.db_name}` OWNER TO {frappe.conf.db_user}")
 	root_conn.close()
 
 
diff --git a/frappe/tests/test_commands.py b/frappe/tests/test_commands.py
index 1de2365713..034236cb22 100644
--- a/frappe/tests/test_commands.py
+++ b/frappe/tests/test_commands.py
@@ -6,7 +6,9 @@ import gzip
 import importlib
 import json
 import os
+import secrets
 import shlex
+import string
 import subprocess
 import unittest
 from contextlib import contextmanager
@@ -511,6 +513,77 @@ class TestCommands(BaseTestCommands):
 
 		self.assertEqual(conf[key], value)
 
+	def test_different_db_username(self):
+		site = frappe.generate_hash()
+		user = "".join(secrets.choice(string.ascii_letters) for _ in range(8))
+		password = frappe.generate_hash()
+		kwargs = {
+			"new_site": site,
+			"admin_password": frappe.conf.admin_password,
+			"root_password": frappe.conf.root_password,
+			"db_type": frappe.conf.db_type,
+			"db_user": user,
+			"db_password": password,
+		}
+		self.execute(
+			"bench new-site {new_site} --force --verbose "
+			"--admin-password {admin_password} "
+			"--db-root-password {root_password} "
+			"--db-type {db_type} "
+			"--db-user {db_user} "
+			"--db-password {db_password}",
+			kwargs,
+		)
+		self.assertEqual(self.returncode, 0)
+		self.execute("bench --site {new_site} show-config --format json", kwargs)
+		self.assertEqual(self.returncode, 0)
+		config = json.loads(self.stdout)
+		self.assertEqual(config[site]["db_user"], user)
+		self.assertEqual(config[site]["db_password"], password)
+		self.execute("bench drop-site {new_site} --force --db-root-password {root_password}", kwargs)
+		self.assertEqual(self.returncode, 0)
+
+	def test_existing_db_username(self):
+		site = frappe.generate_hash()
+		if (user := frappe.conf.db_user) is None:
+			user = "".join(secrets.choice(string.ascii_letters) for _ in range(8))
+			if frappe.conf.db_type == "mariadb":
+				from frappe.database.mariadb.setup_db import get_root_connection
+
+				root_conn = get_root_connection(frappe.flags.root_login, frappe.flags.root_password)
+				root_conn.sql(f"CREATE USER '{user}'@'localhost'")
+			else:
+				from frappe.database.postgres.setup_db import get_root_connection
+
+				root_conn = get_root_connection(frappe.flags.root_login, frappe.flags.root_password)
+				root_conn.sql(f"CREATE USER {user}")
+		password = frappe.conf.db_password or frappe.generate_hash()
+		kwargs = {
+			"new_site": site,
+			"admin_password": frappe.conf.admin_password,
+			"root_password": frappe.conf.root_password,
+			"db_type": frappe.conf.db_type,
+			"db_user": user,
+			"db_password": password,
+		}
+		self.execute(
+			"bench new-site {new_site} --force --verbose "
+			"--admin-password {admin_password} "
+			"--db-root-password {root_password} "
+			"--db-type {db_type} "
+			"--db-user {db_user} "
+			"--db-password {db_password}",
+			kwargs,
+		)
+		self.assertEqual(self.returncode, 0)
+		self.execute("bench --site {new_site} show-config --format json", kwargs)
+		self.assertEqual(self.returncode, 0)
+		config = json.loads(self.stdout)
+		self.assertEqual(config[site]["db_user"], user)
+		self.assertEqual(config[site]["db_password"], password)
+		self.execute("bench drop-site {new_site} --force --db-root-password {root_password}", kwargs)
+		self.assertEqual(self.returncode, 0)
+
 
 class TestBackups(BaseTestCommands):
 	backup_map = {