The Allison J71 was a single spool turbojet engine, designed and built in the United States. It began development in 1948 as a much modified J35, originally designated J35-A-23.

The Allison Engine Company was an American aircraft engine manufacturer. Shortly after the death of James Allison in 1929 the company was purchased by the Fisher brothers. Fisher sold the company to General Motors, which owned it for most of its history. It was acquired by Rolls-Royce plc in 1995 to become the US subsidiary, Rolls-Royce North America.