Keith Alexander (born Keith Buckley; sometimes credited as Keith Alexander Buckley) is an Australian actor best known for his work in the United Kingdom. Originally from Sydney, he moved to the UK in 1965. He also spent time the United States, where he worked on The Ed Sullivan Show providing the English-language voice of the Italian puppet mouse Topo Gigio.

Alexander's UK television credits include Softly, Softly (1966), The New Avengers (1976), Minder (1979) and The Day of the Triffids (1981). On the big screen, he had roles in Submarine X-1 (1968), Superman (1978), Hanover Street (1979) and All About a Prima Ballerina (1980).