"With President Trump's support, I'm ready to fight for your family in the U.S. Senate," Hagerty said in a statement during his campaign launch.
The 59-year-old Republican enters the race as one of the top-tiered GOP candidates vying for the position being vacated by outgoing Republican Sen. Lamar Alexander. Currently, trauma surgeon Manny Sethi is the only other prominent Republican who has filed to run for the seat.
Hagerty promised to support Trump's judicial nominations, as well as Trump's mission to build a wall along the U.S.-Mexico border.
"Serving in President Trump's administration was the honor of a lifetime, but when I saw the threat to Tennessee and our country from the Democrats' socialist agenda, I felt called to act," Hagerty said.
Hagerty has served in a number of executive positions ranging from chief financial officer, to chairman and chief executive officer. He also founded his own private equity and investment firm.
On the Democratic side, Nashville attorney and former Army helicopter pilot James Mackler has also entered the Senate race.
Mackler's team criticized Trump's endorsement of Hagerty's campaign, highlighting that voters will have a choice between someone "handpicked" by an administration that has hurt Tennessee — particularly in trade and health care — and an Iraq war combat veteran.
Mackler dropped out of the 2018 contest to replace Republican former U.S. Sen. Bob Corker, stepping aside when former Democratic Gov. Phil Bredesen opted to run. Bredesen lost by about 11 points to Republican U.S. Sen Marsha Blackburn.
Republicans have held both Tennessee Senate seats since 1994.