The pilot was rescued in the Yellow Sea by the South Korean coast guard and returned to the Kunsan Air Base, the 8th Fighter Wing said in a statement, Reuters reported.
The cause of the emergency was being investigated, it said.
The unit commander, Colonel Matthew Gaetke, said he was grateful for the pilot's recovery and that he was in good condition, the statement said.
The air base located in the South Korean west coast city of Gunsan is one of the two main air bases used by the US military in the country.