Mayo began his career at Rangers and has previously had loan spells with Dunfermline Athletic, Partick Thistle and Kilmarnock.

Mayo was born the day after Rod Wallace scored a hat-trick that helped Rangers beat Motherwell 6–2 in March 2000.

[citation needed] Mayo featured and scored for Rangers in a 5–0 pre-season win over Oxford United at Ibrox and has also played in three Scottish Challenge Cup games for Rangers Colts, making it to the competition's semi-final stage in 2020, after captaining the side for a 2–0 quarter-final win over Wrexham.

[5] Mayo made his debut in a 0–0 draw at home to Queen of the South, receiving a man of the match award for his performance.

[8] Mayo moved on a season-long loan to Scottish Championship side Dunfermline Athletic in September 2020.