He started climbing as a student at Wilmslow Grammar School. Whilst studying geology at Imperial College London, he led his first expedition to the Ecuadorian Andes where he made first British ascents within the El Altar massif as well as assisting David Kirke of the Dangerous Sports Club glide from the summit of Chimborazo. In 1986, he was made a National Officer of the British Mountaineering Council. Shortly after his appointment, he led a bold traverse of Chogolisa and Bride Peak in the Karakoram which was later documented in his book Coming Through. The book also gave an account of his ascent of Menlungtse with Chris Bonington and Alan Hinkes in 1988. Other climbing achievements included winter ascents of the Croz Spur on the Grandes Jorasses and the Eiger North Face.
His book Himalaya Alpine-style, co-authored with Stephen Venables, was published after his death in 1995.
The Andy Fanshawe Memorial Trust
His widow Caroline and a group of friends established The Andy Fanshawe Memorial Trust after his death which provides grants to allow disadvantaged young people to experience the outdoors. The Trust also acts as a memorial to Jane Thomas, who died in the Cairngorms in 1994.
- 1988 Menlungtse West (7023 m) FA via West Ridge. Summit attained with Alan Hinkes (UK), with Chris Bonington (UK), David Breashears and Steve Shea (both USA) in support.
- "Imperial College El Altar expedition report". Retrieved 2009-03-29.
- "BMC Profile (Google Cache)". Retrieved 2009-03-29.
- "Imperial College Mountaineering Club", In Memoriam 1993.
- "Observer article". The Guardian (London). Retrieved 2009-03-29.
- "Andy Fanshawe Memorial Trust profile". Retrieved 2009-03-29.
- Bonington, Chris (1989). "Menlungtse Western Summit". American Alpine Journal (New York, NY USA: American Alpine Club) 31 (63): 284–286. ISBN 0-930410-39-4.
- Fanshawe, Andy, Coming Through: Expeditions to Chogolisa and Meniungtse, Hodder & Stoughton Ltd, 1990, (ISBN 0-340-52079-5)
- Venables, Stephen and Fanshawe, Andy, Himalaya Alpine Style: The Most Challenging Routes on the Highest Peaks, Baton Wicks, 1999, (ISBN 1-898573-39-5)