McGuinness made his debut on the inter-county scene at the age of nineteen when he was selected for the Dublin junior team. He played one championship season with the junior team, culminating with the winning of a Leinster medal in 1949. McGuinness subsequently joined the Dublin senior team during the 1950–51 league. During his career he won one Leinster medal and one National Football League medal. He retired from inter-county football due to injury in 1958.