Hanlon played primarily for Hamilton Academical – he signed for the Accies as a teenager in 1913 a week after being selected for Scotland at junior level,[2][6] featuring regularly for much of that time.
[3] He moved to Heart of Midlothian in 1916[7] but only played in one Scottish Football League match[3] during his initial three years at Tynecastle Park and was away from the club for much of the time serving in World War I.
He returned to Hamilton in late 1919 (and was a Lanarkshire Cup winner in 1920) then signed for Hearts again in 1922,[2][7] but failed to become established there, serving lower-division loans at Bathgate and Alloa Athletic.
[3] Hanlon was a noted athlete (often competing under the pseudonym 'Harris'),[2][6] his speciality being middle-distance running and particularly the half mile, recording a 1min 55sec time in a meeting at Shawfield Stadium in 1922.
[6] He won multiple track events with his regiment (Royal Scots) in a post-war Rhine Army Sports Championship in 1919;[2][6] during the conflict itself, he was employed as a dispatch runner.