Robert Dean Nesen (January 22, 1918 – November 14, 2005) was an American car dealer and diplomat who served as the U.S. Assistant Secretary of the Navy (Financial Management and Comptroller) from 1972 to 1974 and as United States Ambassador to Australia from 1981 to 1985.

He worked for the Air-Research Corp. until 1942, when he joined the United States Navy, serving in World War II until 1946.

Nesen started in the automobile business a few year later, opening an Oldsmobile car dealership in Oxnard.

The business continued to grow in what became known as the "Thousand Oaks Auto Mall" and took on many more franchises; from Subaru and Hyundai in the 1970s and 1980s to high-end exotic brands like Rolls-Royce and Bentley in the 1990s.

[1] In 1981 and 1987, there was press speculation that President Reagan would name Nesen United States Secretary of the Navy, but this never happened.