Shatner is best known for playing the indomitable Captain Kirk in the Star Trek franchise.
He appeared in the original TV series in the 1960s and later starred in a series of films and remains inextricably tied to the character in the public imagination.
Shatner is now the oldest person to ever travel to space, breaking the record set in July by 82-year-old Wally Funk.
He was joined on the flight by Blue Origin vice president Audrey Powers, satellite company co-founder Chris Boshuizen and tech CEO Glen de Vries.
Blue Origin: William Shatner
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Before launch, messages from those onboard Blue Origin's first flight were read out.
Ms Funk told the new crew to savour the day and said: "I hope this flight will be the most fantastic experience of your life as it was mine."
The company did not reveal the cost of tickets, though Shatner travelled for free.
During the livestream of the historic event, Blue Origin stressed the safety of the launch after the company's culture had been criticised by current and former employees in an online essay.
Shatner's blasting off is the latest development in the space tourism boom.
Richard Branson, 71, launched into space on one of his Virgin Atlantic rocketships in July and was followed nine days later by Bezos, 57.
In September, Elon Musk's SpaceX launched its first private flight, though its charismatic founder did not join the four passengers into orbit.