The International Motor Sports Association is an American auto racing sanctioning body. It was started by John and Peggy Bishop in 1969 with help from Bill France Sr. of NASCAR. IMSA began the Camel GT series in the 1970's and moved up to the beloved IMSA GTP series in 1980's with fierce competition between Lolas, Marches, Porsche 962s and Nissans. IMSA was sold by Bishop in 1989 and became Professional SportsCar Racing. After a period of decline, IMSA was revived with the formation of the American Le Mans Series.

It currently sponsors the American Le Mans Series, the Star Mazda series, the STRANA Super Trucks series, and the Panoz GTS/GT/Pro series.