William McKay (August 24, 1906 - June 1977) was a Scottish footballer who played for Bolton Wanderers and Manchester United in the 1930s. He also played for East Stirlingshire, Hamilton Academicals and Stalybridge Celtic. He helped Manchester United 1935-36 (as champions) and 1937-38 to rise from the second division.

McKay joined Manchester United in March 1934. He helped United prevent relegation from the second division at the end of the 1933-34 season and rose to fifth place in 1934-35. He was part of the successful promotion campaign of 1935-36 when United won the Second Division title. The following season, however, they were directly transferred back to the second division, but McKays four goals in four games at the end of the 1937-38 season helped the club to retreat to second place and thus regain first division status. The "Red Devils" ended the 1938-39 season in 14th place.

McKay's career was interrupted by World War II and ended the football league in the first half of the 1940s, despite being featured in the Manchester United war games. During the war he also made guest appearances for Stockport County and Port Vale, where he played at the Old Recreation Ground in Port Vale's 4-2 loss to rivals Stoke City.

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