Harry Henry Hartz (December 24, 1896 – September 26, 1974) was an American racing driver and auto mechanic.

On Thanksgiving Day of that same year he was driving during pre-race test run at a track in Los Angeles when he struck and killed both a photographic journalist and the racecar builder and blackface comedian George L.

Hartz was badly burned and injured in a crash in 1927 at the Rockingham Speedway in Salem, New Hampshire, requiring him to spend the next two years in hospitals.

[2] Together with Billy Arnold as driver, the combination was successful, and they won the 1930 Indy 500 race and also took the national championship for the year.

[4] During mid-August 1934, he set 72 new AAA stock car records at the Bonneville Salt Flats course in Utah in a Chrysler Imperial Airflow coupe.

[5] At the end of the month, Hartz drove the same car from Los Angeles to New York City and set an economy record of 18.1 miles per US gallon (13.0 L/100 km; 21.7 mpg‑imp), and without having to add water at any time during all of these performance runs.