The son of John McIntosh, who played football for Claremont and St Kilda, McIntosh was the youngest of three children. His sister, Karlene, played tennis for Western Australia, and his brother, Nathan, played senior football for Subiaco, later spending two years on West Coast's list without playing a senior game. McIntosh attended Scotch College in Swanbourne, playing football for his school and the Dalkeith-Nedlands Junior Football Club. He also represented Scotch College in athletics, winning the state hurdles events over 200m and 400m.
While capable at either end of the ground, McIntosh most famous for playing at full back, and in 2006 was named as the full-back in the club's best team ever over its 20-year existence (since 1987). He won a club best and fairest in 1998, and has been an All Australian.
McIntosh was a very athletic player, and it was often reported that he could run a 100m race in 11.0 seconds. The wiry McIntosh was also deceptively strong. Wayne Carey, on Talking Footy once credited him as the strongest opponent he'd ever played against, which surprised a lot of people, including the show's host Bruce McAvaney.