Kelso was manager of Hibernian for one season,[1] before taking over as manager of newly promoted Woolwich Arsenal in 1904.[2] He managed the club for four years, during which time he took the side to the FA Cup semi-finals two seasons in a row; however, his best in the league was only seventh (in 1906-07).[3]
With the club starting to run into financial trouble and with results declining, Kelso resigned in 1908 to returned to Scotland to manage a hotel;[4] but was tempted back down south to become manager of Fulham in 1909. He stayed with the Cottagers for 15 years, making him their longest-serving manager.[5] After retiring from football he ran a couple of pubs in the Hammersmith area and was chairman of the Football League Managers and Secretaries Association.[5]
Kelso died in London, in 1935, aged 63. He is buried in East Sheen[5]