USS New Mexico (BB-40) was a battleship in service with the United States Navy from 1918 to 1946. She was the lead ship of a class of three battleships, and the first ship to be named for the state of New Mexico. Her keel was laid down on 14 October 1915 at the New York Navy Yard, from which she was launched on 23 April 1917 and commissioned on 20 May 1918. New Mexico was the U.S. Navy's most advanced warship and its first battleship with a turbo-electric transmission, which helped her reach a maximum speed of 21 knots.

The New Mexico class was a class of three super-dreadnought battleships built for the United States Navy in the late 1910s. The class comprised three ships: New Mexico, the lead ship, Mississippi, and Idaho. Part of the standard series, they were in most respects copies of the Pennsylvania-class battleships that immediately preceded them, carrying over the same main battery arrangement of twelve 14-inch (356 mm) guns, but now increased to 50-caliber. They incorporated several other improvements, including a better arrangement of the secondary battery that increased its usability, a clipper bow that improved seakeeping, and an experimental turbo-electric propulsion system adopted on New Mexico. Like the other standard-type battleships, they had a top speed of 21 knots that allowed the fleet to operate as a tactically homogeneous unit.