Republican senators met privately Tuesday to select Richard as a successor to former Senate President Pro Tem Tom Dempsey.
The full Missouri Senate is expected to vote Wednesday on the pro tem position. Because Republicans control the chamber, Richard is expected to be elected to the leadership post.
Dempsey resigned in August and now works at a St. Louis-based lobbying firm.
Republican senators also Tuesday chose Sen. Mike Kehoe of Jefferson City to replace Richard as majority leader. Sen. Bob Onder of Lake St. Louis was chosen to succeed Kehoe as assistant majority leader.