Otto Wilhelm Rudolf Caracciola (30 January 1901 – 28 September 1959), more commonly Rudolf Caracciola (pronounced [ʁuːdɔlf kaʁaːtʃiːɔlɑ]), was a racing driver from Remagen, Germany. He won the European Drivers' Championship, the pre-1950 equivalent of the modern Formula One World Championship, an unsurpassed three times. He also won the European Hillclimbing Championship three times – twice in sports cars, and once in Grand Prix cars. Caracciola raced for Mercedes-Benz during their original dominating Silver Arrows period, named after the silver colour of the cars, and set speed records for the firm. He was affectionately dubbed Caratsch by the German public, and was known by the title of Regenmeister, or "Rainmaster", for his prowess in wet conditions.

Caracciola began racing while he was working as apprentice at the Fafnir automobile factory in Aachen during the early 1920s, first on motorcycles and then in cars. Racing for Mercedes-Benz, he won his first two Hillclimbing Championships in 1930 and 1931, and moved to Alfa Romeo for 1932, where he won the Hillclimbing Championship for the third time. In 1933, he established the privateer team Scuderia C.C. with his fellow driver Louis Chiron, but a crash in practice for the Monaco Grand Prix left him with multiple fractures of his right thigh, which ruled him out of racing for more than a year. He returned to the newly reformed Mercedes-Benz racing team in 1934, with whom he won three European Championships, in 1935, 1937 and 1938. Like most German racing drivers in the 1930s, Caracciola was a member of the Nazi paramilitary group National Socialist Motor Corps (NSKK), but never a member of the Nazi Party. He returned to racing after the Second World War, but crashed in qualifying for the 1946 Indianapolis 500. A second comeback in 1952 was halted by another crash, in a sports car race in Switzerland.