Circuit Judge Mark Mahon will become the new chief judge for the 4th Judicial Circuit, which covers Clay, Duval and Nassau Counties.
The results of a secret ballot were announced Thursday. The circuit's 54 judges selected Mahon over Judge Lance Day.
Mahon will technically be an interim chief judge until the end of July 2015, when Moran's term expires. Mahon says he is "honored and humbled" by the selection.
The position opened up when Chief Judge Donald Moran announced that he will retire in January. He has served has chief judge since March 1993.
A chief judge administers the circuit and county courts, overseeing the budget, judicial assignments and courthouse rules.
Mahon was appointed to the bench in 2007 by former Gov. Charlie Crist. He served on the state legislature for seven years.