Wilson, who was health minister under former premier Mike Harris, was elected interim leader this morning during a meeting of the PC caucus.
He'll stay on the job until the Tories can hold a leadership race and schedule a convention to pick their next leader.
Wilson isn't the only one getting a new job today as the legislature returns for the first time since the June 12 election.
Members of the legislature will elect a new Speaker this afternoon after all 107 MPPs are sworn in this morning, including Premier Kathleen Wynne.
Liberals Dave Levac — who held the position before the election was called — and Shafiq Qaadri are running, but Progressive Conservative Rick Nicholls and New Democrats Paul Miller and Cheri DiNovo also want the job.