Republic Airlines was an airline in the United States that operated from 1979 until it merged with Northwest Airlines in 1986. Republic was formed by the merger of North Central Airlines and Southern Airways on July 1, 1979. Their headquarters were at Minneapolis–Saint Paul International Airport, in what is now Fort Snelling in unincorporated Hennepin County, Minnesota. The former headquarters is now Delta Air Lines Building C.

Northwest Airlines Corp. was a major airline in the United States from 1926 until its merger with Delta Air Lines in 2010. The merger made Delta the largest airline in the world until the American Airlines–US Airways merger in 2013.