Republican state Rep. Paul Farrow of Pewaukee is scheduled to be sworn in as a state senator on Dec. 14 after winning an uncontested special election for an open seat.
Farrow won the election on Tuesday to replace Rich Zipperer, who resigned in August to become Gov. Scott Walker's deputy chief of staff.
Farrow is able to take his seat in the Senate earlier than others elected in the regular November election because he was chosen in a special election to fill a vacancy.
With Farrow's win, Republicans will hold an 18-15 majority in the Senate starting in January.
Farrow was first elected to the state Assembly in 2010.