Louis Frederick Dietrich (September 13, 1868 – June 11, 1947) was an automobile dealer and politician in Ontario, Canada.
Around 1888, he apprenticed as a blacksmith in Baden and set up shop in his hometown in 1892.
In 1893, he became a dealer for John Deere farm implements.
In 1909, he moved to Waterloo and, two years later, he became a dealer for International Harvester.
During his term as mayor, the Kitchener-Waterloo Municipal Airport was opened.