O'Connell attended Waverly primary and Paddington technical college.
O'Connell, who played in the halves, was an Easts junior who debuted with the club in the 1956 at the age of 19. In the years 1956-59, he scored 177 points from 11 tries and 72 goals, he made around 60 appearances for the Eastern Suburbs club, many as captain.
In 1960, Barry joined the Manly Warrigah club, playing 85 matches, many of those also as captain. He played for Manly in the years 1960-64. After leaving Manly he took up a role as a captain-coach in the rural NSW town of Mudgee. His final year of rugby league,1967, was spent captaining the Dunedoo club, who played in the Group 14 competition, to their first premiership, and was named as that competitions leading player.