Yes, they have been in many different forms of motor racing, including F1 (where they won two world championships). Supplied Indy cars, touring cars, and other series.
Alfa Romeo is a car
Alfa Romeo was created on 1910-06-24.
Alfa Romeo is Italian.
Alfa Romeo is made in Italy.
The first Formula 1 car to be supplied by Alfa Romeo was at the 1950 British GP. Where they won almost every race with same driver.
Alfa Romeo makes their own cars.
Alfa Romeo Arna was created in 1983.
Alfa Romeo MiTo was created in 2008.
Alfa Romeo Giulia was created in 1962.
Alfa Romeo Alfasud was created in 1971.
Alfa Romeo RM was created in 1923.
Alfa Romeo SZ was created in 1989.