He attended St. Patrick's College in Wellington, and obtained a B A from Victoria University of Wellington.
Before entering politics, he worked in the social welfare sector, and was also a bus driver in Wellington.
He was MP for the seat of Eastern Hutt from the 1990 election until the 1996 election, when the electorate boundaries were changed.
He won Rimutaka in 1996 and held the seat until the 2008 election, which he did not contest, retiring from national politics.
He met Toni Reeves in 2000; she was executive secretary to Otago M P David Parker When they married in 2003 he was 51, she was 25. Paul Swain and Tony Reeves-Swain have one daughter, and two sons from his first marriage.
After the Wallaceville wedding, which was described in the March 19 'Leader', the reception took over the Mayfair Café. Guests included Rex Kirton, Wayne Guppy and their wives, Prime Minister Helen Clark, and Cabinet ministers.
Paul held a number of ministerial portfolios, including Associate Minister of Finance, Minister of Commerce, Minister of Communications, Minister of Corrections, Minister of Immigration, Minister for Information Technology, Minister of Labour, Minister of Statistics, Minister for State Owned Enterprises, Minister of Transport, and Associate Minister for Economic Development.
The December 8, 2004 'Leader' printed a photo of the Swains with Madeline; Toni's first child, and Paul's first daughter.
After the 2005 election, Swain decided not to seek a Cabinet post in the new government; an October 2 'Leader' article quoted a wish to see more of his new daughter, and ability to devote more time to electorate issues..
Swain was made a Companion of the Queen's Service Order (QSO) in March 2009 for services as a Member of Parliament.
He has been employed by the Crown as their lead negotiator for a settlement of historical grievances with Ngāti Porou.[
N.Z. Railway and Locomotive Society; Rimutaka MP Paul Swain and former Wellington & Manawatu Railway Co. carriage.
Plateau School; refurbished library opened by Nathaniel Plester, Maria Moen, Rimutaka MP Paul Swain.
St Joseph's School; administration block opened; Koraunui Marae kaumātua Ted Puhia and Paul Swain, M P with tukutuku panels