Concord is a city in Contra Costa County, California, USA. As of the 2000 census, the city had a total population of 121,780. Until 1995 the city was the eastern terminus of the Concord line of Bay Area Rapid Transit (BART) commuter train system; it has since been extended eastward to Pittsburg/Bay Point and the Concord line is now the Pittsburg/Bay Point - Daly City Line. Concord has been primarily a bedroom community over the last forty years, but during the last decade corporations such as ChevronTexaco and Bank of America have established extensive back-office operations there, diversifying the local economy.

Concord is also the home of the annual Concord Jazz Festival and the Concord Records jazz record label.

Concord's Mount Diablo High School is home to several acclaimed California academies, specifically the Digital Safari, a three-year program involving the integration of multimedia with the core curriculum through integrated, project-based learning. The headquarters of the Kabul Soccer Club is located in Concord.

Concord's De La Salle High School is home for the record winning streak of 151 games set by the football team between 1992 and 2004. During that span, De La Salle won 12 California North Coast sectional championships, and was named national champion five different times (once by ESPN, four times by USA Today).

Jazz musician Dave Brubeck was born in Concord, as was actor Tom Hanks, Olympic gold-medalist Natalie Coughlin and mixed martial artist Gil Castillo.

Concord is also home to the 11 time World Champion Blue Devils Drum and Bugle Corps. The corps is made up of talented musicians from around the world. The Concord Blue Devils are the most decorated drum and bugle corps in the history of Drum Corps International.