A+D Museum, Art museum in Los Angeles Arts District, California.

The A+D Museum is an architecture and design museum at 900 E 4th Street in the Downtown Los Angeles Arts District, in a former warehouse. Natasha Sandmeier is executive director and Camille Elston managing director. Its exhibitions, talks and education programs cover architecture, interiors, landscape, fashion, product, graphic and film/theatre design.

The A+D Museum was founded in 2001 by Stephen Kanner and Bernard Zimmerman, with Kanner drawing inspiration from a similar museum he had visited in Helsinki. It opened in January 2001 in the Bradbury Building at 304 South Broadway, in a space donated by Ira Yellin. After the building was sold in 2003, the museum moved to a temporary site on the Sunset Strip in West Hollywood, then to 5900 Wilshire Boulevard in 2006 and 6032 Wilshire Boulevard in April 2010. Displaced by the Metro Purple Line extension, it returned downtown to a former warehouse in the Arts District in summer 2015.

The museum presents exhibitions that treat architecture and design as languages people use and encounter every day. Visitors can observe how spaces and objects shape daily life and why thoughtful choices in design matter to everyone.

The museum occupies a former warehouse at 900 E 4th Street in the Arts District; its entrance is at street level. Exhibitions are spread across the building's floors, reached by stairs, ramps and lifts. The museum is a 501(c)(3) nonprofit funded by public, government, foundation and corporate donations, and it is a member of the American Alliance of Museums.

The museum houses the Stephen Kanner Education Center for Architecture and Design, which runs the ARkidECTURE design program and partners with groups such as Heart of Los Angeles (HOLA) and the Petersen Automotive Museum. Students use the center for workshops, critiques, lectures and film screenings.