John Henry Cattley was born in London, the son of a post office worker. He was active in gymnastics competitions around London in the 1900s along with his brother Albert Edward Cattley and in 1908 was selected as a member of the British gymnastics squad to compete at the Olympic Games. Participating in the team event, the Great Britain team finished in last place out of eight countries. Cattley was a motor car driver and mechanic by profession and served in World War I as a driver-mechanic with the 66th Auxiliary Company of the Mechanical Transport of the Royal Army Service Corps, including an overseas tour in Germany. He later resided in West Sussex until his death in 1961.