The Virgin Group founder's own plane, Unity, was released from a carrier craft for a few minutes of floating weightlessness and views of Earth from high above.
After being freed at 13km, the piloted plane climbed to 86km before gliding down to a runway. Nasa and the Federal Aviation Administration say outer space starts at 80km above sea level.
"The whole thing, it was just magical," Branson said on his return.
Unity is in its fifth year of testing without accident, after tragedy-marred years of development with earlier aircraft since 2004. Virgin Galactic flights will begin with more than 600 paying customers from next year, willing to cough up US$250,000 ($360,000) a ticket.
Blue Origin says it will fly higher. Its New Shepard is designed to carry six people and flies without a pilot, with both the rocket and capsule reusable. The capsule lands via parachutes. Ticket prices are yet to be announced.
Branson has said the aim is to "make many more people be able to access space". Yesterday he announced a sweepstakes drawing for two seats on a future flight.
Space has, in its most positive light, previously been about government-funded scientific discovery and wonders. Amazing feats have been conjured such as precise landings of spacecraft on planets years after launches. It has been about demonstrating what can be achieved, enhancing collective knowledge, and people everywhere have felt inspired by it.
Now we are in a more opaque era of private commercial involvement.
Elon Musk's SpaceX has been a contractor for Nasa on missions with its reusable Falcon rocket. It is planning private multi-day astronaut missions over the next year.
Branson and Bezos are buying for themselves - and will be selling - the expensive experience of being an astronaut. For the foreseeable future most of those people lucky enough to "access space" will be part of the wealthy elite. You can dream of seeing space if you're rich enough.
Former Canadian astronaut Chris Hadfield, there to see Branson's flight, had a positive take. "I'm just so delighted at what this open door is going to lead to now. It's a great moment."
Branson, an airman, showman and adventurer, can be viewed as part of a tradition of people using their wealth to, in part, break new ground in interesting areas.
With so much of the world's wealth in the hands of a few, what they focus on matters. The interest in space is a break from the recent past where at least some of the ultra-rich have concentrated on philanthropy after making their fortunes.
It is also happening as this planet could clearly do with much more investment in technologies to reduce the urgent impacts of climate change as the world suffers scarily extreme heatwaves and fires in the Northern Hemisphere. It would be far more helpful for the rest of us if they could compete to get rid of carbon emissions.
This month's space flights are milestones, but they are also about expensive out-of-this-world escapism from what's happening on Earth.
