It hadn't occurred to me before, but yes: the Tin Man from the Wizard of Oz is clearly a robot. Like other movie robots, such as Star Trek's Data, he's trying to become more human. Many other cinema robots are practically human already or comfortable in their artificial nature.
This is 1 of 100 movie robots described in an impressive list at Paste magazine. Among them are B-movie monsters, childhood heroes, and other creatures you wouldn't normally think of as robots, but are.
-via Jonah Goldberg