Career
Milligan, who played as a forward, played professionally in Scotland, England, and Ireland between 1937 and 1949. Club career
Born in Johannesburg, Dudley began his career with hometown side Johannesburg Rangers before going on trial with Scottish club Dundee in late 1937. After failing to get a contract, Milligan instead signed for Clyde in December 1937.
After scoring nine goals in ten League games, Milligan moved to English side Chesterfield in November 1938.
During World World War II, normal League football was suspended, and Milligan guested for a number of teams in Ireland including Linfield, Larne, Distillery and Dundalk. After the League resumed in 1946, Milligan returned to Chesterfield, before moving to Bournemouth & Boscombe Athletic in August 1947.
By October 1948 Milligan had moved to Walsall, and in 1949 he returned to Ireland to play with Ballymena United. International career
Milligan played international football for both South Africa and Ireland, representing the latter at the 1939 British Home Championship.