Kennedy first played Gaelic football at juvenile and underage levels with the St. Margaret's club.
[1] He was still eligible for the minor grade when he was promoted to the club's senior team, but enjoyed little in terms of success.
He won a Leinster MFC medal in 1976, however, his subsequent three-year spell with the under-21 team without success.
[2] Kennedy joined the senior team in 1979 and won the first of six Leinster SFC medals that year before losing the All-Ireland final to Kerry.
Kennedy also won a Railway Cup medal with Leinster in 1988, the same year he was named as the All-Star left corner-back.