Guy Laliberte, a former street artist, will become the world's seventh space tourist.
"I've been introduced as many things in the past -- fire-breather, entrepreneur, performer, partier," he told a news conference. "But today to be introduced as a private space explorer is an enviable and unbelievable feeling."
He had dreamed of traveling in space since he visited a Soviet exhibition on space in Canada in 1967, he said.
Laliberte, 49, will blast off from the Russian launch site on the Kazakh steppe aboard a Soviet-designed Soyuz rocket with a Russian cosmonaut and a U.S. astronaut on September 30.
He declined to say exactly how much the trip had cost him except that he had paid a similar amount to previous space tourists who paid between $20 million and $35 million.
Laliberte is now training at the Russian cosmonaut center Star City near Moscow.
"I have rediscovered my sense of adventure, the very essence of what stimulated for many years when I lived and worked on the street," he said.
The forbes.com Web site estimates that Laliberte has a net worth of around $2.5 billion.
Cirque du Soleil is credited with revitalizing the circus industry with acrobats, live music and dance. It began with 20 street performers in 1984 but now employs around 4,000 people around the world.
Laliberte also plans a show from space. He wants to perform a poem on the Earth's water scarcity from the International Space Station during his 12-13 day mission.
"I'm working at this point on an artistic production project, an original one I hope, that will surprise, will entertain and will achieve the goal of communicating in a massive way this poem."
The Russian federal space agency launches a space craft periodically to relieve the crew of the International Space Station, and it is during these missions that private citizens or space tourists can pay to travel into space.