By-election were held on 5 May 2005 to fill vacancies in Tongatapu and Niuas following the appointment of Feleti Sevele and Sione Haukinima to the cabinet.
Elections by popular vote took place on 5 May 2005 to replace vacant seats in Tongatapu and Niuas, after Feleti Sevele and Sione Haukinima were appointed to the government.