He made his League of Ireland debut for Dundalk at
Waterford on 25 September 1988. After two years at
Oriel Park, during which he shared the PFAI Young Player of the Year Award in 1989/90, he signed for Liverpool. Due to injury he failed to make a single first team appearance before getting a free transfer to Middlesbrough at the end of the 1992/93 season. After 3 appearances for Hereford he came home to sign for Bohemians where he scored 22 goals in 83 league games over three seasons. He signed for
Shamrock Rovers in the summer of 1996, making his debut in a preseason friendly against
Heart of Midlothian. His first of many goals for the Hoops came in a friendly win against
Crewe Alexandra. Three weeks later, he scored his first competitive goal in a 2–2 draw against
Shelbourne in the
League of Ireland Cup. His first league goal came against
Bray Wanderers on 13 September 1996. In his
first season with Shamrock Rovers he was the joint top goalscorer in the
League of Ireland Premier Division, winning Player of the Month in February 1997. The following season, he was the team's top goalscorer with 15 league goals. During the six years he played with Rovers he scored 46 goals in 145 league appearances and a total of 65 goals in 190 appearances, including one goal in two appearances in European competition. Having completed his time with Shamrock Rovers, he spent one season with Bray Wanderers before retiring. Cousins was capped six times by the
Irish Under 21 team at the start of his career, scoring four goals. == Coaching career ==