Sir John Kenneth McAlpine KCMG (21 July 1906 – 11 January 1984) was a New Zealand politician of the National Party. He was the Member of Parliament for Selwyn from 1946 to 1966, when he retired.
He was Minister of Railways in the First National Government from 1954 to 1957. In the Second National Government from 1960 to 1966 he was Minister of Railways and Minister of Transport. He was made a C.M.G. in 1970 and a K.C.M.G. in 1977.