Concord is located at northeast of San Francisco, 22 miles northeast from Oakland, 65 miles southwest of Sacramento, and 51 miles north of San Jose.

The focal point of downtown Concord is Todos Santos Plaza, which encompasses an entire city block and is known for its farmers market, free summer concerts, and large number of surrounding restaurants. Much of the area immediately around downtown has recently been redeveloped, with new high-density apartment and condominium projects to take advantage of the proximity to public transportation and to the area surrounding the park. Despite this, some crime and homelessness remain issues in the downtown area.

To the north and east of downtown is the older residential area of Concord, with many homes dating back to before World War II. In the far northern edge of town is a primarily industrial area, dominated by the Tesoro Golden Eagle Refinery (which is actually not located within city limits). The southeastern area of the city, centered along Clayton Road, is primarily residential and was mostly developed in the 1960s and 1970s. In the southwest area of the city is the primarily Latino neighborhood known as Four Corners, centered around the intersection of Monument Boulevard and Oak Grove Road.

Concord is bordered on the west by Pleasant Hill and the unincorporated community of Pacheco, on the south by Walnut Creek, on the southeast by Clayton, on the northeast by Pittsburg and the unincorporated community of Bay Point, and on the north by the unincorporated community of Clyde. Although it shares no border with Concord, Martinez is located almost immediately adjacent to Concord on the northwest. The North Concord BART station is also known as Martinez BART.