John Hardy "Johnny" Isakson (born December 28, 1944), is an American politician, who has been the Republican junior United States Senator from Georgia since 2005. Previously, he represented Georgia's 6th Congressional district in the House from 1999 to 2005.

A second-generation Swedish-American, Isakson was born in Atlanta and currently lives in the nearby suburb of Marietta. He served in the Georgia Air National Guard from 1966 to 1972, leaving service as a staff sergeant. Shortly after graduating from the University of Georgia, he opened the first Cobb County office of Northside Realty, a prominent Atlanta-area real estate firm. He became company president in 1979, a post he held for 22 years, during which Northside became the biggest independent real estate company in Georgia. He is a member of Sigma Alpha Epsilon Fraternity.

Isakson and his wife Dianne have three children: John, Kevin, and Julie.