Born in the United States of America in 1947, Lethbridge took his undergraduate degree at the University of Kent at Canterbury in 1969 before completing a Master"s degree at McMaster University in 1970 and then a Doctor of Philosophy at Street John"s College, Cambridge in 1975.
As an academic Lethbridge has been associated most prominently with Fitzwilliam College, Cambridge, where he was Fellow from 1973-1992 and Senior Tutor from 1982-1992. He then moved to Royal Holloway, University of London to take a Chair in French Language and Literature and was successively Head of Department, Dean of the Graduate School and Vice-Principal. In 2005 he returned to Fizwilliam as Master, a position he held until his retirement on 30 September 2013.
He conducts research and teaches postgraduate students in association with Cambridge University"s Department of French, where he was a lecturer until 1994.
He is now Honorary Professor of Nineteenth-Century French Literature in the University. His main interest is late 19th century France and specifically the relationship between literature and visual arts in that period.
In the context of the 2013 Royal Academy exhibition he gave a lecture on Manet and the Writers of his Time. He has held Visiting Professorships at the University of California at Santa Barbara and at the University of Melbourne and now also holds the position of Emeritus Professor of French Language nd Literature at the University of London.
Between 2001 and 2006 he was Honorary President of the Society of Dix-neuvièmistes, a group founded in Dublin in 2001, mainly comprising British and Irish academics with an interest in 19th century France.
In 2012, he was appointed Commandeur dans l’Ordre des Palmes Académiques (the highest rank in the Order), a chivalric order established in 1955 for services to French culture and scholarship, having been an ordinary member since 1988. From 2010 - 2013 he was also the Provost of the Gates Cambridge Trust. In 2012, after the Boat Race between the universities of Oxford and Cambridge was disrupted by a protester against elitism, Lethbridge was reported in the Daily Mail as strongly criticising left-wing politicians for criticising Cambridge University, saying that it was the opposite of elitist and could not "try any harder" to reach out to applicants from all walks of life.
He called critics "lazy" and "uninformed", and told the Daily Telegraph, that there was a problem with a mindset which "doesn"t want anyone to fail".
