Dwight Bowling appeared Wednesday in U.S. District Court in Greenville.
Court records show the 56-year-old pleaded guilty to two counts of taking a minor across state lines, from Mississippi to Alabama, for sex.
Bowling pleaded guilty to one count of obstruction for trying to get someone else to lie to investigators.
A sentencing date was not immediately set.
Bowling coached 28 years at Smithville High School in Monroe County, Miss., before retiring and taking a similar job at Sulligent High in Sulligent Ala.
He was the coach for the Alabama school when he was arrested last September in Mississippi, on his way home from a football game.
Viewers with disabilities can get assistance accessing this station's FCC Public Inspection File by contacting the station with the information listed below. Questions or concerns relating to the accessibility of the FCC's online public file system should be directed to the FCC at 888-225-5322, 888-835-5322 (TTY), or firstname.lastname@example.org.