In 1893 he joined Newton Heath, playing 19 league games and scoring once before joining Luton Town in 1894. He helped Luton gain election to the Football League and played in Luton's first-ever league match on 4 September 1897, a 1–1 draw away to Leicester Fosse. He played 27 times that season, leaving at the end of it to join Barnsley. He scored 3 times in 63 league games for Barnsley before retiring in April 1901 to become Barnsley's secretary-manager.
In May 1920, he was appointed manager of Portsmouth. He guided Portsmouth from Division Three South to the First Division, but resigned due to ill health in May 1927 before he could manage Pompey in the top flight. In September 1927 he returned to management with Luton Town, but with his health declining further, he resigned in December 1929 and retired from football. McCartney died in Edinburgh at the age of 66.