Incumbent Sheriff Bobby Shoffner is facing a challenge for the office from Hodgenville Mayor Terry L. Cruse.
The winner of the Democratic primary on May 18 will face Republican challenger Jack R. Smith in November.
Shoffner, 51, was elected sheriff in 2002 after serving as deputy for 10 years. He has been in law enforcement 24 years including a five-year stint with Hodgenville City Police.
He was re-elected in 2006, defeating Cruse in the Democratic May primary by 700 votes (1,179 to 1,877).