His father Henry Simpson Lunn (1859-1939) was a Methodist priest and founder of the travel company Lunn 's Travel Agency, which later transformed to Lunn Poly and today is part of the TUI Group.
The young Arnold Lunn studied at Balliol College, Oxford University. He was a passionate mountaineer and founded in 1909 the Oxford University Mountaineering Club. Since his father's company also organized ski trips to Switzerland at the time, Arnold Lunn was often present there.
He soon became a well-known skiers and developed the modern rules of the downhill and slalom, which at the British National Championships in Mürren in the Bernese Oberland for the first time in 1921, or 1922 application and were taken over in 1928 by the World Federation FIS. Also in 1928 he led in St. Anton am Arlberg with Hannes Schneider, the first Arlberg - Kandahar race through. Lunn was also the organizer of the first Alpine World Skiing Championships in Mürren.
Originally Lunn told the Methodist faith of his father, and said, in his early years, even publicly against Catholicism from. After a conversation with a theologian and crime writer Ronald Knox, his religious views changed and more and more he converted to Catholicism in 1933, he had condemned earlier. He wrote numerous Catholic apologetic works. These were as Hilaire Belloc well received by Catholic fellow writers.
- The Mountains of Youth (1924 )
- Switzerland and the English ( 1944)
- Mountains and Memory (1948 )
- The Story of Skiing (1952 )
- The Kandahar Story ( 1969)