The Contra Costa Times is a daily newspaper based in Walnut Creek, California, U.S.. The paper serves Contra Costa and eastern Alameda counties, in the eastern part of the San Francisco Bay Area. The Times also publishes four other editions under different titles (West County Times, East County Times, San Ramon Valley Times, and Valley Times) but essentially the same content, serving distinct communities within its circulation area. In 2007 the Contra Costa Times was merged with ANG Newspapers to form a new entity called Bay Area News Group-East Bay, which is in turn owned by MediaNews Group. It is currently published as an edition of the San Jose Mercury News.

The final editions of the newspaper under the names The Contra Costa Times, San Ramon Valley Times, East County Times, Tri-Valley Herald and San Joaquin Herald were scheduled to be published on November 1, 2011, however BANG announced on October 27, 2011 that it would retain several of the mastheads and combine the Tri-Valley Herald and San Joaquin Herald, along with the The Valley Times under a new Tri-Valley Times masthead. Other BANG mastheads to be retained included the Oakland Tribune, Hayward Daily Review, Fremont Argus and West County Times which were to be combined under a new East Bay Tribune title.

Contra Costa County (Spanish for "opposite coast") is a primarily suburban county in the San Francisco Bay Area of the U.S. state of California. As of the 2010 census, it had a population of 1,049,025. The county seat is Martinez.

In prehistoric times, particularly the Miocene epoch, portions of the landforms now in the area (then marshy and grassy savanna) were populated by a wide range of now extinct mammals, known in modern times by the fossil remains excavated in the southern part of the county. In the northern part of the county, significant coal and sand deposits were formed in even earlier geologic eras. Other areas of the county have ridges exposing ancient but intact (not fossilized) seashells, embedded in sandstone layers alternating with limestone. Layers of volcanic ash ejected from geologically recent but now extinct volcanos, compacted and now tilted by compressive forces, may be seen at the site of some road excavations. This county is an agglomeration of several distinct geologic terranes, as is most of the greater San Francisco Bay Area, which is one of the most geologically complex regions in the world. The great local mountain Mount Diablo has been formed and continues to be elevated by compressive forces resulting from the action of plate tectonics and at its upper reaches presents ancient seabed rocks scraped from distant oceanic sedimentation locations and accumulated and lifted by these great forces. Younger deposits at middle altitudes include pillow lavas, the product of undersea volcanic eruptions.