It comes after the company, led by billionaire Richard Branson, completed its first fully crewed flight to the edge of space in July.
The firm hopes to start commercial flights next year after completing several more test missions.
It had previously sold tickets at $250,000 apiece but stopped in 2014 after a fatal accident.
In a statement, boss Michael Colglazier said last month's successful test mission had renewed public interest in the firm's offer.
"Leveraging the surge in consumer interest following the Unity 22 flight, we are excited to announce the reopening of sales effective today," he said.
"As we endeavour to bring the wonder of space to a broad global population, we are delighted to open the door to an entirely new industry and consumer experience."
Virgin Galactic is currently vying with Blue Origin, run by Amazon's Jeff Bezos, and Space X, owned by Tesla's Elon Musk, to develop a space tourism market.
Days after the Virgin mission in July, Mr Bezos took part in the first fully crewed test flight of one his own planes into space.
He is expected to sell tickets on future Blue Origin flights for between $200,000 and $300,000.
Space X meanwhile last year undertook the first crewed test flight of its Dragon spacecraft to the International Space Station.
Under a partnership with Nasa it plans to transport astronauts to the ISS in future. It also plans to send three tourists on a 10-day trip later this year.
For its flights, Virgin said it prospective tourists would have the option to buy single seats, friends and family packages, or reserve the whole plane.
Those who have already expressed an interest in the flights will get to reserve their seats first. About 600 tickets had been sold before it previously halted sales.
The firm's next spaceflight, Unity 23, is expected to take off in late September from Spaceport America in New Mexico.