FATAL: role "username" does not exist — how to fix

psql: error: connection to server on socket "/var/run/postgresql/.s.PGSQL.5432" failed: FATAL:  role "me" does not exist

Quick fix: Create a role matching your login: sudo -u postgres createuser --interactive (or sudo -u postgres psql -c "CREATE ROLE me LOGIN CREATEDB;"), then createdb me. Or connect explicitly: psql -U postgres -h localhost.

What it means

Without -U, psql uses your operating-system username as the PostgreSQL role, and a database with the same name. Fresh installs only have the postgres role, so psql as user me fails.

Fix on Linux

sudo -u postgres createuser --interactive      # name: me, superuser? choose
sudo -u postgres createdb -O me me
psql                                            # now works

Or in SQL:

sudo -u postgres psql

CREATE ROLE me WITH LOGIN PASSWORD 'secret' CREATEDB;
CREATE DATABASE me OWNER me;

Fix on macOS (Homebrew)

Homebrew creates a superuser named after your macOS user, not postgres. So role "postgres" does not exist is the common error there:

createuser -s postgres

or connect with your own user: psql -d postgres.

Fix with Docker

The superuser is whatever POSTGRES_USER was set to on first start (default postgres):

docker exec -it db psql -U postgres

Changing POSTGRES_USER later has no effect because the data directory already exists. Either create the role manually or remove the volume to re-initialize (this deletes the data):

docker compose down -v

In application config

Check the username in your connection string, e.g. postgresql://app:secret@localhost:5432/appdb. ORMs (Django, Rails, Prisma) then need the database to exist too; FATAL: database "appdb" does not exist is fixed with createdb -O app appdb.

Last updated 2026-10-28.