John Andrew Horn (born September 7, 1968) is an American attorney.

Currently with the law firm King & Spalding, he is a former United States Attorney for the Northern District of Georgia.

[3][4] Prior to joining the U.S. Attorney's Office in 2002, Horn was an associate in the special matters group at King & Spalding.

[5] Before that, Horn clerked for Judge Harold L. Murphy of the Northern District of Georgia, and for Stanley F. Birch, Jr. of the Eleventh Circuit Court of Appeals.

During his 15-year tenure with the U.S. Attorney's Office in Atlanta, Horn served as deputy chief of the Narcotics & Organized Crime Drug Enforcement Task Force, then Appellate Division chief and first assistant U.S. attorney under Sally Yates.