He joins a long list of candidates seeking the nomination: Cherilyn Eagar, Chris Stewart, Howard Wallack, John Willoughby, David Clark and Chuck Williams.
The incumbent, Democratic Rep. Jim Matheson, said he is running in the adjacent 4th Congressional District.
The 2nd District includes all of Salt Lake City and southern Davis County, then sweeps down the west side of the state to Washington County.
Buck grew up in a farming family in Idaho, where he saw his family's farm foreclosed upon and was left homeless.
He played football in college, was an All-American defensive lineman at BYU and won the Outland Trophy, given to the nation's best interior lineman. He was a first-round draft pick for the Cincinnati Bengals and played for them in Super Bowl XXIII.
He won a Super Bowl ring with the Washington Redskins in 1992.
Buck bought a ranch in Manti after retirement and later moved to Highland. He said several months ago he planned to run for Congress in either the 2nd District or the 4th District. Buck lives in the 3rd District.
"Our nation's economy and finances have been devastated by Barack Obama and the Washington, D.C., liberals," Buck said. "I'll fight for a leaner, smaller and constitutionally limited federal government one that is pro-free-market, pro-taxpayer, pro-family and fiscally sound."
Buck and his wife, Roxi, have four children and two grandchildren.