Gillom signed with the Browns, an AAFC team coached by Brown, in 1947. He handled all of the team's punting chores and played as a utility end on both offense and defense. Gillom's Cleveland teams won three straight AAFC championships before the league dissolved and the Browns were absorbed by the NFL. The Browns won the NFL championship in 1950 and repeated in 1954 and 1955. Gillom was a consistent punter, never averaging below 41.2 yards per kick in a season. His abilities declined in his later years, however, and he was released during the 1956 season. Gillom attempted a comeback in 1961 with the New York Titans of the American Football League, but failed to make the team. He moved to Los Angeles and worked as a security guard for the rest of his life. Gillom died of a heart attack in 1985. He was named in 2007 as a Cleveland Browns Legend, a grouping of the team's best-ever players.