Rodney Kohler "Rod" Johnston (September 2, 1937 – March 30, 2018) was an American attorney and Republican politician.

In 1982, he was the Republican nominee for United States Congress in Wisconsin's 5th congressional district, but was defeated by Jim Moody.

After leaving the service, he enrolled at George Washington University Law School, where he received his J.D.

Johnston died March 30, 2018, at his home on Tybee Island, Georgia, at the age of 80.

He was survived by his three children, Scott, Julie and actress Kristen Johnston.