Louis Meyer (July 21, 1904 – October 7, 1995) was an American racing driver who was the first three-time winner of the Indianapolis 500. He is generally regarded as one of the finest racers of his generation. Meyer is perhaps best known as the driver who started the tradition of drinking milk after winning the Indianapolis 500.

Meyer was born in Yonkers, New York on July 21, 1904, the son of French immigrants. Meyer was raised in Los Angeles, where he began automobile racing at various California tracks.

Early in his career, Meyer helped prepare the Miller driven by Frank Elliott in 1926, destroking the engine to bring it within the 91+1⁄2 cu in (1,499 cc) displacement limit permitted by the rules. Meyer went with the car when it was sold in 1927 to Fred Holliday (of Holliday Steel Company) as the Jynx Special (a morbidly ironic name, since Jimmy Murphy had been killed in it in 1924). He would be mechanic for Wilbur Shaw in the Indianapolis 500 that year. Meyer also served as co-driver, taking the car from seventh place up to sixth.

In 1928, Phil Shafer's intended Miller entry went up for sale, and Alden Sampson bought the car for Meyer. Meyer passed the rookie test, qualified thirteenth, and took the lead on Lap 181; he won by a margin of 25 seconds, at an average speed of 99.5 mph (160.1 km/h). The same year, Meyer won a 200 mi (320 km) event at the 1+1⁄2 mi (2.4 km) board track at Altoona, Pennsylvania, at an average speed of 117.02 mph (188.33 km/h), in a Stutz-Miller. He earned consistent points finishes to make him AAA's National Champion. He would claim the title again in 1929 and 1933.

At the 1929 Indianapolis 500, Ray Keech beat Meyer, only to be killed at Altoona two weeks later, the season's second 200 mi (320 km) event there, which Meyer won, averaging 110 mph (180 km/h).

Meyer managed only fourth place at the 1930 Indianapolis 500, and the Great Depression curtailed racing. That, plus the closure of many board tracks as unsafe, led Meyer to concentrate more on dirt track racing.

In 1933's 500, at the wheel of the Tydol Special Miller, Meyer took the lead on Lap 129. Meyer steadily increased his lead from there, until he was fully four laps up on the field by the checkered flag. Despite lifting later in the race, Meyer's race average, 104.16 mph (167.63 km/h), was still a record. By winning his second 500, he joined a fairly exclusive club. Meyer started the tradition of drinking milk (buttermilk at the time) in victory lane that year, when he drank a glass. Following his 1936 victory, he drank from a glass milk bottle instead, as most race winners have done since.

Meyer followed his success in 1935, forming Champion Drivers, Inc., to promote racing, along with nine other top racers.