Yes, AC Milan and Inter Milan share one stadium: the Stadio Giuseppe Meazza, universally known as San Siro.
This groundshare is rare among top European rivals. The clubs alternate home matches, with the stadium's curvature and tiered design creating an intense atmosphere. Each club maintains its own museum, offices, and training facilities elsewhere.
Both clubs have proposed a new shared stadium ("The Cathedral") adjacent to the current site, aiming for 2028–2030 completion. San Siro may be partially preserved or redeveloped. Until then, the historic venue remains the dual home of the Derby della Madonnina.