Northwestern Highway or North-Western Highway refers to the following: United States M-10 (Michigan highway), a highway near Detroit, Michigan also known as Northwestern Highway; Northwestern Highway (auto trail), a highway connecting the states of Illinois and Wyoming.

Australia Calder Highway, a highway in Victoria, originally gazetted as North-Western Highway in 1925 and renamed in 1928; Sunraysia Highway, a highway in Victoria, originally gazetted as North-Western Highway in 1947-8 and renamed in 1972; Mitchell Highway, a highway in New South Wales, originally gazetted as North-Western Highway in 1928 and renamed in 1936.