Frostop was a national chain of drive-in restaurants affiliated with the Frostop brand of root beer. The first location was opened by L. S. Harvey in 1926 in Springfield, Ohio.
By the mid-1960s, the chain had four locations in Birmingham. Each offered "pure beef" hamburgers and frothy mugs of Frostop root beer and orange drink. The restaurants were distinguished by their oversized mug-shaped signs. The sign at Frostop's Five Points West location (which was managed in 1965 by Bob Sykes) was later modified for Marsh Bakery.