Frank Glennon played for the Shamrock Rovers in the League of Ireland before he was selected to play on and captain the 1948 Irish Olympic football team in London, which lost in its only match to the Netherlands by a score of 3-1. Glennon was born in Dublin, the son of insurance agent Francis Xavier Glennon, the namesake and founder of the family company, later known as Glennon Insurance Brokers. He later followed his father’s footsteps in the insurance industry and became the chairman of the company, serving until his death.