He died at the Jersey Hospice at the age of 67.
Thompson, a recipient of the Michael Lucas Sporting Hero award, steered Leonis into one of the best amateur boxing clubs in the British Isles.
He had dedicated his life to coaching generations of boxers and was rightfully proud of the club's achievements in taking on and beating county teams.
He prided himself on making sure his boxers were in a prime state of fitness before entering the ring - a policy which really did mean the island punched above its weight.
His illness prevented him from running with the Olympic Torch when it was in Jersey, but he was later visited by officials who carried the flame in a lantern to present him with his torch - a moment of pride for him and his family.