Dundee born, Alex began his career with junior club, Parkmore F.C. He made his first team debut for Dundee against Hibs in Sept 1901. Dundee won the match 1-0. His brother Johnnie played in the same game, at outside left, it was the only time they played together for Dundee.
Moving to Aberdeen in 1904 he became club captain. After short spells with Portsmouth and Forfar, he finished his professional career with St Johnstone in 1913.
A wheelwright to trade, he was employed at Rosyth Naval Base.
Joining the army in 1916, Gunner Halkett, 143620, R.F.A., went to France 17th December 1916. He died 21st February 1917, age 36, and is buried at Sailly au Bois Military Cemetery, France, leaving behind a widow.