The Kawasaki Ninja EX250cc R (codenamed EX250; previous generations had market-specific names) is a motorcycle in the Ninja sport bike series from the Japanese manufacturer Kawasaki originally introduced in 1986. As the marque’s entry-level sport bike,the motorcycle has undergone few changes throughout its quarter-century lifetime, having received only three substantial redesigns. In some markets the Ninja 250 has been succeeded by the Ninja 300.

Since 2008, the bike is marketed as the Kawasaki Ninja EX250cc R in all markets. It is also referred to by its platform designation, EX250, to which a generational suffix is attached. In the United States, previous models (EX250-E/F/G/H) were already being marketed as members of the Ninja family of sport bikes, while outside of the U.S. the bike was known variously as the ZZR-250, ZX-250, or as the GPX-250R. One of the earliest models, the EX250-C, was given the name GPZ-250