The Dong Feng 31 is a third-generation long-range, road-mobile, three stage, solid-fuel rocket intercontinental ballistic missile (ICBM) in the Dongfeng missile series developed by the People's Republic of China. It is designed to carry a single 1-megaton thermonuclear weapon. It is a land-based variant of the submarine-launched JL-2. It is operated by the People's Liberation Army Rocket Force (PLARF). In 2009, the Chinese inventory was estimated as under 15 DF-31 missiles and under 15 DF-31A missiles. US Air Force National Air and Space Intelligence Center estimates that as of June 2017, five to ten Mod 1 and over fifteen Mod 2 launchers were operationally deployed.

An intercontinental ballistic missile (ICBM) is a ballistic missile with a range greater than 5,500 kilometres (3,400 mi), primarily designed for nuclear weapons delivery. Conventional, chemical, and biological weapons can also be delivered with varying effectiveness, but have never been deployed on ICBMs. Most modern designs support multiple independently targetable reentry vehicle (MIRVs), allowing a single missile to carry several warheads, each of which can strike a different target. The United States, Russia, China, France, India, the United Kingdom, Israel, and North Korea are the only countries known to have operational ICBMs.