[1] Leydon first played Gaelic football to a high standard as a student at St Jarlath's College in Tuam.
[2] Leydon's club career with Dunmore McHales also began around this time and he won his first Galway SFC medal in 1961.
[8] Three successive All-Ireland SFC titles followed for Leydon, beating Kerry in the finals of 1964 and 1965 and Meath in the 1966 decider.
Leydon's last big occasion for Galway was when he lined out at left corner-forward in the 1971 All-Ireland final defeat by Offaly.
[13] Leydon retired from inter-county football in 1972 when his job as regional sales director with Cantrell and Cochrane required him to move to Cork.