The Champion Spark Plug 100 Mile an Hour Club was a group formed to honor drivers who completed the Indianapolis 500 at an average speed of 100 miles per hour or faster. It was formed in 1935, and continued to be recognized through 1969. It was sponsored by Champion Spark Plugs, and was the brainchild of M.C. deWitt, the company's advertising manager. During its heyday, it was considered one of the most prestigious honors in motorsports (the Indy car counterpart to NASCAR's famous Darlington Record Club), and membership was highly sought after by drivers.
A total of 124 drivers were inducted as members, with 1930 winner Billy Arnold named the club's first member.