Otto August Kuhler (July 31, 1894 – August 5, 1977) was an American designer, one of the best known industrial designers of the American railroads. According to Trains magazine he streamstyled more locomotives and railroad cars than Cret, Dreyfuss and Loewy combined. His extensive concepts for the modernization of the American railroads have repercussions onto the railways worldwide until today. In addition he was a prolific artist of industrial aesthetics and of the American West in general.

Kuhler (pronounced "Cooler") became a US citizen in 1928. Eight years before he had married Simonne Gillot, daughter of a Belgian doctor. They had one daughter, Winona (married name: Zabriskie), and one son, Renaldo, who became known as a natural-history museum artist.