He was a goalkeeper for the Old Malvernians before joining the Chelsea board in 1931, in doing so becoming the youngest director (aged 26) in the Football League.
Mears was a Royal Marine during the Second World War, and his duties included the security arrangements for Prime Minister Winston Churchill's bunker.
Mears' tenure as chairman of Chelsea saw them win their first First Division title in 1954–55, and it was he who subsequently gave in to pressure from the Football League for the club not to take its place in the inaugural European Champions Cup the following season.
He later managed the representative London XI side during its 1955–58 Inter-Cities Fairs Cup campaign; the team reached the final, losing on aggregate to FC Barcelona.
As such, he was a key figure during England's preparations to host the 1966 World Cup, and was involved in the furore when the Jules Rimet trophy was stolen.