Roma were ordered to close the Curva Sud section of the Stadio Olimpico where their most dedicated fans sit because of racist chants aimed at AC Milan striker Mario Balotelli during Monday's 2-2 Serie A draw at the San Siro.
A disciplinary tribunal said Roma supporters chanted "The red-and-blacks are a team of blacks", referring to the colours of the Milan shirt, and persistently booed Balotelli when he had the ball.
Inter Milan were also fined and ordered to shut off a section of their ground for one match because of discriminatory chants aimed at Napoli fans during Sunday's match in the southern city.
The tribunal said the game, which ended 4-2 to the home side, was marred by chants of "Naples cholera, you are the shame of all Italy; smell of shit, smell of dogs, the Neapolitans are coming... You are not human beings".
The ruling means Inter will play Sunday's derby with city rivals AC Milan without the support of hardcore fans who usually sit in the Curva Nord.
Italian football authorities have cracked down on discriminatory as well as racist chanting this season, announcing automatic stadium closures as a penalty.
This has angered many fans who have long traded insults. Ultras from teams including Naples have campaigned against the rules.
A selection of smaller fines were also given to Napoli, Juventus, Milan, Catania and Lazio for charges including aggressive chanting and the use of firecrackers.
(Reporting by Naomi O'Leary; editing by Toby Davis)
