Pugh was educated at Prescot Grammar School and Maidstone Grammar School. He graduated from Durham University, attending St Cuthbert's Society, where he studied Philosophy.
Formerly a religious studies teacher and Head of Philosophy and Religious Studies at Merchant Taylors' School, Crosby, Pugh has lived in Southport since 1974. He also taught at Salesian College (later Savio High School) in Bootle.
Pugh joined the Liberal Party in 1977. Pugh served on Sefton Metropolitan Borough Council, representing Birkdale, from 1987 until his election to Parliament. At the time of his election, Pugh was leader of the council (from 1992), and of the Sefton Liberal Democrats.
First elected to the House of Commons in the 2001 general election, in his first parliamentary term, Pugh served on the Transport, Local Government and Regions Select Committee and was Liberal Democrat education spokesperson with responsibility for schools. Following his re-election to Parliament in 2005, he served as shadow spokesperson for Transport and Health, and, subsequent to the election of Nick Clegg as party leader worked with Vince Cable as Shadow Treasury spokesperson. In the 2007 leadership election, John Pugh supported Nick Clegg in preference to Chris Huhne.
With the formation of the coalition government in 2010 he was appointed as Co-Chair of the Liberal Democrat Parliamentary Committee for Health and Social Care, a position he relinquished at the end of 2013 to focus on producing a report examining the social and economic issues facing the North.
In his party's 2015 leadership election, John Pugh supported Tim Farron in preference to Norman Lamb.
In December 2015, Pugh voted to extend the bombing of ISIL targets in Iraq to Syria.
On 19 April 2017, Pugh announced that he would not be standing in the 2017 general election.
Amongst Pugh's campaigning interests is public sector IT, specifically around the role Open Source Software might play. Pugh has argued that the public sector could reduce costs by increasing use of Open Source Software and has accused the BBC of effectively giving Microsoft illegal state aid in only making their iPlayer download service available on Windows computers (at the time).
Pugh has interests in mental health policy. In October 2009, Pugh introduced a private members' bill under the 10-minute rule calling for more local control over the NHS.
Locally in Southport, Pugh is interested in saving local pubs, and also in the drinking culture of the UK. Pugh sees cheap alcohol deals in supermarkets as one of the major problems causing pub closures, and fuelling the culture. He also took the fight for Local Post Offices to 10 Downing Street.
In Transport, Pugh has long campaigned for the reinstatement of the Burscough Curves, and is working with local groups such as the Ormskirk, Preston and Southport Travellers' Association (OPSTA) and the Southport Rail Transport Forum (SRTF) to save services from Southport to Manchester Piccadilly
Pugh supports Amnesty International, with whom he is reported to have had close ties with the Formby & Southport Group over a number of years.
In 2013, he became one of the few Liberal Democrat MPs to vote against the Marriage (Same Sex Couples) Bill.
He is married to Annette with three daughters and a son. He moved to Southport in 1974.
Pugh's interests include philosophy, computers, weight-lifting and supporting Liverpool F.C.2010– Co-Chair of the Liberal Democrat Parliamentary Committee for Health and Social Care
2008–10 Shadow Treasury Spokesperson
2006–07 Shadow Health spokesperson
2005–06 Shadow Transport spokesperson,
2002–05 Shadow Ministerial Spokesman, Education