Williams, who recently toured Australia, made the comment while appearing as a guest on the popular "Late Night with Dave Letterman Show".
"The Australians are basically English rednecks. 'You down there, how are ya? Good to see you. Hello','' he said.
Speaking to Triple M radio show host Eddie McGuire in Melbourne on Wednesday, Rudd said: "First of all, I think Robin Williams should go and spend a bit of time in Alabama before he frames comments about anyone being particularly redneck."
"That's my first response."
Redneck, which commonly refers to a poor white person in the southern states of America, is also a derogatory term in Australia - generally referring to a stupid, country person with ignorant views.