"He's a lovely Englishman. He's going to be king of England one day," Shatner, 90, told Entertainment Tonight. "He's a lovely, gentle, educated man, but he's got the wrong idea."
"The prince is missing the point," added Shatner, who this week became the oldest person to travel to space. "The point is these are the baby steps to show people [that] it's very practical. You can send somebody like me up into space."
Shatner's comments come in response to the Duke of Cambridge's strong criticism of recent space tourism, in which he said the "world's greatest brains and minds" should be focused on repairing the planet.
"I think that ultimately is what sold it for me — that really is quite crucial to be focusing on this [planet] rather than giving up and heading out into space to try and think of solutions for the future," Prince William told BBC Thursday morning.
However, Shatner, who had an emotional reaction upon returning to Earth on the Blue Origin this week, said the trip held a different meaning and hopefully inspired ways to protect the planet.
"The idea here is not to go, 'Yeah, look at me. I'm in space.' The landing that consumed all that ... energy and people to take a look and go, 'Oh, look at that.' No," Shatner told ET. "I would tell the prince, and I hope the prince gets the message, this is a baby step into the idea of getting industry up there, so that all those polluting industries, especially, for example, the industries that make electricity ... off of Earth."
"We've got all the technology, the rockets, to send the things up there ... You can build a base 250, 280 miles above the Earth and send that power down here, and they catch it, and they then use it, and it's there," he added. "All it needs is ... somebody as rich as Jeff BezosJeffrey (Jeff) Preston BezosDorsey's exit shakes up Twitter future The dangers of anarchy in space Health risks of space tourism: Is it responsible to send humans to Mars? MORE [to say], 'Let's go up there.' "
The British royal also said that billionaires and political leaders should address other issues on Earth, to which Shatner said he "of course" agreed, but that it shouldn't stop space tourism.
"So fix some of the stuff down here," Shatner said. "But we can curl your hair and put lotion on your face at the same time."