Warren is a city in Macomb County in the U.S. state of Michigan. The 2020 Census places the city's population at 139,387, making Warren the largest city in Macomb County, the third largest city in Michigan, and one of Metro Detroit's core cities. The city is home to a wide variety of businesses, including General Motors Technical Center, the United States Army Detroit Arsenal, home of the United States Army TACOM Life Cycle Management Command and the Tank Automotive Research, Development and Engineering Center (TARDEC), the headquarters of Big Boy Restaurants International, and Asset Acceptance. The current mayor is James R. Fouts, who was elected to his first mayoral term in November 2007.

The settlement was formally incorporated as the Village of Warren from Warren Township on April 28, 1893 out of one square mile bound by 14 Mile Road and 13 Mile Road to the north and south, and in half-a-mile east and west of Mound Road. The small village grew slowly, and had a population of 582 in 1940 and 727 in 1950, while the larger surrounding township grew at a much quicker pace. Much of this growth was due to the construction of the Chrysler's Truck Assembly plant in 1938, the Detroit Arsenal Tank Plant in 1940 to support the WW II effort, and the General Motors Technical Center between 1949 and 1956.