Warren could mean:

Animal husbandry and related

Animal husbandry

Warren (domestic), a rabbitry for the breeding and raising of domestic rabbits. Warren is also used for rabbit or hare burrows in the wild.

Warren

Forest law

Warren (free) ("Free warren"), a type of hunting franchise under the Anglo-Norman Forest law

Warren

Metaphor

In metaphoric use, warren refers to a tight agglomeration of inferior accommodations, such as a slum.

Warren

People

Warren G. Harding, 29th President of the United States

Warren Beatty, American actor

Warren Christopher, former Secretary of State of the United States

Warren E. Burger, former Chief Justice of the Supreme Court

Warren Buffett, American businessman and entrepreneur

Warren Hastings, first Governor-General of India

Warren Zevon, American singer and musician

Warren Truss, Australian politician

Other

Warren abstract machine, a Prolog (software) engine

Warren Commission, which investigated the assassination of John F. Kennedy

Warren Cup, a Roman antiquity

Warren's Gate, an archaeological site

Warren's Skipper, a type of butterfly

Warren Wagon Train Raid, historic incident in Texas