The Mazda 787 and its derivative 787B are Group C sports prototype racing cars that were developed by Japanese automobile manufacturer Mazda for use in the World Sportscar Championship, All Japan Sports Prototype Championship, and the 24 Hours of Le Mans from 1990 to 1991. Designed to combine a mixture of the Fédération Internationale du Sport Automobile (FISA) Group C regulations with the International Motor Sports Association (IMSA) GTP regulations, the 787s were the last Wankel rotary-powered racing cars to compete in the World and Japanese championships, using Mazda's R26B engine.

Mazda Motor Corporation , also known as simply Mazda, is a Japanese multinational automotive manufacturer headquartered in Fuchū, Hiroshima, Japan. The company was founded on January 30, 1920, as Toyo Cork Kogyo Co., Ltd., a cork-making factory, by Jujiro Matsuda. The company acquired Abemaki Tree Cork Company. It changed its name to Toyo Kogyo Co., Ltd. in 1927 and started producing vehicles in 1931. The name Mazda was derived from Ahura Mazda, the god of harmony, intelligence and wisdom in Zoroastrianism, as well as from the surname of the founder. Mazda is one of the largest automakers in Japan and the world. In 2015, it produced 1.5 million vehicles for global sales, of which nearly one million were made in Japan and the rest in various other countries. It ranked as the 15th-largest automaker by production volume globally in 2015. Mazda is known for its innovative technologies, such as the Wankel engine, the SkyActiv platform, and the Kodo Design language. It also has a long history of motorsport involvement, winning the 24 Hours of Le Mans in 1991 with the rotary-powered Mazda 787B. Mazda has several alliances and partnerships with other automakers, such as Toyota, Nissan, Isuzu, Suzuki and Ford.