Rambler is an automobile brand name that was first used by the Thomas B. Jeffery Company between 1900 and 1914.

The Thomas B. Jeffery Company was an American automobile manufacturer in Kenosha, Wisconsin, from 1902 until 1916. The company manufactured the Rambler and Jeffery brand motorcars. It was preceded by the Gormully & Jeffery Manufacturing Company, a bicycle manufacturer. It was the predecessor company to Nash Motors, and thus one of the predecessor companies of American Motors Corporation (AMC) and later Chrysler.