Larne, County Antrim born right half Keiller McCullough was as adept as an attacking force as he was as a defender. He was noted for his effectiveness with his head and was one of the earliest examples of a defensive player “going up” for a corner kick, rising high above the opposing defence. When sometimes employed at inside right McCullough’s cleverness could change a game in a split-second.
Signed in August 1927 by Belfast Celtic from intermediate side Newington Rangers, McCullough made an immediate impact at Celtic Park, earning praise for the way he adapted to the big stage. In his eight seasons with Celtic he won countless honours, though the Irish Cup did elude him. He also represented The Irish League on 6 occasions between 1928 and 1935 while with Celtic, scoring once. His first cap for Ireland came in March 1935 when he played in a 3-1 defeat to Wales at Wrexham, his second cap a loss by the same margin to England that October in Belfast.
Transferred to First Division Manchester City in November 1935 he made his debut immediately at Derby County,but having lost his place in January 1937 he was largely a fringe player. While at Maine Road he added three Ireland caps to the two he won at Belfast Celtic. He left City after scoring once in just eighteen appearances in two years, joining Division Three (South) Northampton Town in March 1938. More usually used at wing-half, with the Cobblers McCullough also filled in as right-back before his Football League career was ended by the outbreak of World War Two after 2 goals in 40 appearances.