Keiko played Willy the whale in three films, all about him being released from captivity and surviving at sea.
Keiko himself was released into the wild near Iceland in July 2002, after a $20m (£11.4m) programme taught him how to catch his own fish.
Once released he swam to Norway, and on Friday died from pneumonia, after medicine doctors gave him didn't work.
Keiko was captured in 1979 as a young calf, and wasn't very well treated until found in 1993 in a Mexico aquarium.
He was the first orca whale rescued from captivity, and scientists hope it will prove other captive whales can be set free too.
Even when he was released Keiko didn't want to live out in the open seas, preferring to live in a Norwegian fjord near his handlers.
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