He represented Ireland at the 1983, 1987, 1991 and 1995 EuroHockey Nations Championships and at the 1990 Men's Hockey World Cup.

He is the father of Ian Sloan, the Ireland, England and Great Britain international.

He also helped Cookstown win the 1986–87 Irish Senior Cup, defeating Banbridge 4–0 in last final to be played on grass.

Sloan was a member of the Ireland team that were silver medallists at the 1978 EuroHockey Junior Championship.

Other members of the team included Stephen Martin, Jimmy Kirkwood and Billy McConnell.

On 18 June 1982, aged 20, Sloan made his senior debut for Ireland in a 7–0 win against Sweden during a EuroHockey Nations Championship qualifying tournament.

Away from field hockey, Martin Sloan served as a director of the Northern Health and Social Care Trust.