In "Star Trek", he, like James T Kirk, steered the Enterprise spacecraft through galaxies, to places where no one else had traveled.
On Wednesday afternoon, the 90-year-old went as himself - and became the oldest person so far to travel into space.
The trip was organized by billionaire Jeff Bezos' space company Blue Origin and the journey itself was similar to the one Bezos himself did in July this year.
Just like it lasted Wednesday's journey for about eleven minutes and Bezos himself was the one who opened the capsule and welcomed the gang back to the ground in Texas, USA.
Philosophical Shatner
"I experienced something I never expected," Shatner told Bezos in Blue Origin's webcast.
While the other passages celebrated with champagne, Shatner was moved to tears and almost philosophical in the conversation with Bezos.
- Everyone needs to see this.
To see all the blue and then suddenly you are out in all the black in space.
Is that how death is?
What you have given me is the deepest experience I can imagine.
It was so touching.
I hope I never lose this feeling.
Four minutes of weightlessness
In addition to William Shatner, the crew also included Audrey Powers, second chief executive of Blue Origin, and the two outside tech CEOs Glen de Vries and Chris Boshuizen.
The journey went to the so-called Karman line about 100 kilometers above the earth, which according to the international Fédération Aéronautique Internationale forms the boundary to space.
The passengers were weightless for about four minutes.