In the 1970s, Wright joined the Vanguard Unionist Progressive Party, and was elected as its Chairman. He stood for the party in North Antrim at the Northern Ireland Constitutional Convention election in 1975, and was elected. He later followed the party leaders in joining the Ulster Unionist Party (UUP), and was elected to Ballymena Borough Council for this new party at the 1981 Northern Ireland local elections, He lost his seat at the 1985 election, and did not stand in 1989, but was re-elected in 1993 and won again in 1997.
Wright stood for election to the Northern Ireland Forum in 1996, but was not elected. In 1998, he resigned from the UUP, and stood unsuccessfully in the 1998 Northern Ireland Assembly election as an independent Unionist. He held his council seat in 2001, before finally standing down in 2005.
Wright was appointed an Officer of the Order of the British Empire (OBE) in the 2001 Birthday Honours for services to Industry and the community. He was promoted to Commander of this Order (CBE) in the 2011 Birthday Honours for services to the Bus Industry. Wright was then knighted in the 2018 New Year Honours for services to the economy and the bus industry. He was awarded the Freedom of the Borough of Mid and East Antrim in Northern Ireland on 18 January 2019.
- "Company History", The Wright Group
- Margaret Canning, "Wrightbus boss drives off with Belfast Telegraph's top business award", Belfast Telegraph, 28 March 2014
- Ted Nealon, Northern Ireland: A Parliamentary Directory, p.227
- "North Antrim 1973-1982", Northern Ireland Elections
- "The Local Government Elections 1973-1981: Ballymena", Northern Ireland Elections
- "Local Government Elections 1985 - 1989: Ballymena", Northern Ireland Elections
- "Ballymena Borough Council Elections 1993-2011", Northern Ireland Elections
- "1996 Forum Elections: Candidates in North Antrim", Northern Ireland Elections
- "North Antrim", Northern Ireland Elections
- "No. 56237". The London Gazette (Supplement). 16 June 2001. p. 13.
- "No. 59808". The London Gazette (Supplement). 10 June 2011. p. 9.
- "No. 62150". The London Gazette (Supplement). 30 December 2017. p. N2.
- "Freedom of the Borough | Mid and East Antrim Borough Council". www.midandeastantrim.gov.uk. Retrieved 24 June 2021.
- "Council to confer Honorary Freedom of the Borough on Sir William Wright CBE in January". www.ballymenatimes.com. Retrieved 24 June 2021.