Titan IV was a family of heavy-lift space launch vehicles developed by Martin Marietta and operated by the United States Air Force from 1989 to 2005. Launches were conducted from Cape Canaveral Air Force Station, Florida and Vandenberg Air Force Base, California.

A heavy-lift launch vehicle is an orbital launch vehicle capable of generating a large amount of lift to reach its intended orbit. Heavy-lift launch vehicles generally are capable of lifting payloads between 20,000 to 50,000 kg or between 20,000 to 100,000 kilograms into low Earth orbit (LEO). As of 2024, operational heavy-lift launch vehicles include the Long March 5 and the Proton-M.