Senator Brent Steele is retiring after the 2016 General Assembly ends.
The 67-year-old Steele says he wants to practice law and spend more time with his family, especially his grandchildren.
Steele has served 20 years as a state lawmaker serving in the Indiana House from 1994 to 2002, representing District 65 – a seat now held by fellow Republican Eric Koch.
When Lawrence County native Becky Skillman became former Gov. Mitch Daniels running mate, Steele was appointed to replace her as senator for District 44, which includes Lawrence, Brown, parts of Bartholomew, Jackson and Monroe counties.
The General Assembly begins in January and ends just before the May primary election.
Republicans will choose a candidate to succeed Steele in the May balloting.