Laurenson was born in Marton, North Island, New Zealand. He was a student at Canterbury University College in Christchurch (now University of Canterbury) where he was directed by Ngaio Marsh, notably in the title role in MacBeth at the Civic Theatre Christchurch in 1962.
He moved to the UK in the mid-1960s and made his film debut in 1969 with a small part in Women in Love, although he also had an uncredited part (as an Oxford rower, playing alongside Graham Chapman) in The Magic Christian.
He has appeared in numerous British Shakespearean productions, notably Richard II, as Rosencrantz in Hamlet, and on radio in the marathon series, Vivat Rex. He also appeared as Piers Gaveston in the 1970 production of Christopher Marlowe's Edward II, opposite Ian McKellen who later recalled that kissing Laurenson "was a bonus throughout the run". Other costume roles included a French courtier in Elizabeth R and the Earl of Lincoln in Shadow of the Tower (1972). In the same year, he took on a more modern role starring as Det. Inspector Napoleon "Bony" Bonaparte in the Australian TV drama series Boney, playing a half-Aboriginal detective. This would be his most high-profile part, although the casting of a non-Aboriginal in the role was attacked by some Australian critics. In 1974 he took the lead role in the TV film The Prison, based on the novel by Georges Simenon, the first instalment in the Thames Television/Euston Films series Armchair Cinema. He also starred as Pink's Father in the 1982 film, Pink Floyd—The Wall.
An accomplished singer, Laurenson took the lead role of Julian Marsh in Gower Champion's musical 42nd Street at the Theatre Royal, Drury Lane, London, and appeared at Greenwich Theatre in Falling Over England with Charlotte Cornwell.
Throughout his career, Laurenson has had guest roles in numerous popular TV series such as Z-Cars, Space: 1999, The Professionals, Armchair Thriller, Hammer House of Horror, Remington Steele, Cagney and Lacey, Hammer House of Mystery and Suspense, Inspector Morse, Bergerac, Boon, Lovejoy, Prime Suspect, Sharpe, A Touch of Frost, Heartbeat, Silent Witness, Taggart, Midsomer Murders, State of Play, Hustle and Spooks.
In 2012, he played the Earl of Westmoreland in the BBC Two adaptations of Henry IV, Parts I and II, and in 2013 he appeared as Professor Hilary Ambrose in Season 2, Episode 5 of the BBC One's Father Brown series. In 2016, he played the role of John Weir in the Netflix series The Crown.
- Women in Love (1969)
- The Magic Christian (1969)
- Elizabeth R (1971, TV)
- Assault (1971)
- Boney (1971–72, TV series)
- The Shadow of the Tower (1972, TV)
- Hammer House of Horror: Rude Awakening (1980, TV)
- The Monster Club (1980)
- Pink Floyd – The Wall (1982)
- Heartbreakers (1984)
- Inspector Morse: The Dead of Jericho (1987, TV)
- The Man Who Fell to Earth (1987, TV movie)
- The Bourne Identity (1988, TV)
- Countdown to War (1989, TV)
- The Man Inside (1990)
- Sharpe (1993, TV)
- A House in the Hills (1993)
- Midsomer Murders: Beyond the Grave (1998, TV)
- Henry IV, Parts I and II (2012, TV)
- The Crown (2016, TV)
- Continuum Companion to Twentieth Century Theatre - Colin Chamber. A&C Black, May 14, 2006 ISBN 0-8264-4959-X page 179|url=https://books.google.com.ph/books?id=cFlFhuVMFGQC&pg=PA179&lpg=PA179&dq=%22James+Laurenson%22+canterbury+student&source=bl&ots=mV9om-qoya&sig=OTkYJh63y9iS-uMYYJkNSrdtguI&hl=en&sa=X&ei=0taeVLmkDIOXuATR0oLICQ&ved=0CBwQ6AEwAA#v=onepage&q=%22James%20Laurenson%22%20canterbury%20student&f=false
- The Theatre of Ngaio Marsh - Brian McNeill published in Art New Zealand No.13 Spring 1979 (with Photograph)|url=http://www.art-newzealand.com/Issues11to20/marsh.htm
- Ian McKellen's homepage Edward II
- "Cast confirmed for BBC Two's cycle of Shakespeare films" (Press release). BBC Drama Publicity. 2011-11-24. Archived from the original on 2011-12-30. Retrieved 2012-07-20.
- BBC Interview with Helen Otter in June 2006