Tim Berry has been the party's chairman since July 2013.
The accountant announced his intention to run for office Saturday morning.
The number two Republican in the House was defeated this week, and now Eric Cantor's party members are looking for a replacement.
The speech will be Mike Pence's first GOP response as governor. He delivered it several times while in Congress.
Governor Mike Pence named a new state auditor Thursday. But what does the state auditor actually do?
Dwayne Sawyer will replace Tim Berry, making Sawyer the first black Republican to hold a statewide office.
State GOP Chairman Eric Holcomb says he has been contemplating stepping down for some time.
The state wants to continue using the Healthy Indiana Plan, or HIP, as its health insurance program for low-income Hoosiers not covered by Medicaid.
The committee approved Monday the Republican budget proposal, which includes increased funding for infrastructure and K-12 education.
The House Republicans' budget does not include the governor's desired tax cuts, but House Democrats want there to be a vote on the proposal.