The Arcimboldi Theater (Teatro degli Arcimboldi) is a theatre and opera house in Milan. It was built over a 27-month period in anticipation of the closure and subsequent nearly three-year-long renovation of Milan's La Scala opera house in December 2001. It is located 4.5 miles from the city centre in a converted Pirelli tire factory, in an area known as Bicocca.

Designed by Vittorio Gregotti in collaboration with Mario Botta and Elisabetta Fabbri, the fan-shaped, two-level, 2,375-seat auditorium was inaugurated with a performance of Verdi's La traviata on 19 January 2002, and went on to allow the continuation of La Scala's 2001/2002 opera season. Following La Scala reopening on 7 December 2004, Teatro degli Arcimboldi expanded its program, hosting performances of jazz, classical and pop music.

The opera house is divided into three volumes: foyer, auditorium and stage. The structure has an essential and compact style, the total area is 18.400 m2 wide and 7.400 m2 are available for the audience and 11.000 for the production. The auditorium holds up to 2346 spectators and it is coated with wooden red panels. The hall is 15 m high, it is curved-shaped and the columns hold the glass wall. The scheme on the ceiling has been studied to improve the acoustic performance.