After a day of intermittent showers, the rain stopped for the official opening by Singapore President SR Nathan on the floating stage in Marina Bay, which will later host some cycling events.
Young drummers and dancers performed by the ceremony, watched by an enthusiastic crowd of 25,000. The Olympic flame was carried to the stage by a large dragon boat and lit by 16-year-old sailing competitor Darren Choy of Singapore. International Olympic Committee (IOC) President Jacques Rogge said he had felt like an expectant father before the games began.
The 12-day event, which will involve 3,500 athletes aged from 14 to 18, competing in 26 Olympic Sports, was the brainchild of Rogge, who hopes it will teach important life and sports skills. "I feel like a father waiting in the delivery room for the birth to come," Rogge, an orthopaedic surgeon by profession, said at a news conference ahead of the opening ceremony.
With so many sports organising their own national, regional and world championships, critics have questioned the need for a Youth Olympics in an already crowded sporting calendar. "It is an ambitious project, we approach this with the necessary humility," Rogge said.
"I am very optimistic that this is going to be the start of a long successful series."
The Austrian city of Innsbruck is scheduled to host the first Winter Youth Olympics in 2012 and Nanjing, China, will stage the second summer games in 2014.
Local media have suggested the event will not attract big crowds, despite an extensive publicity campaign.
There has also been criticism of the cost after the Singapore government said last month it had trebled from the original estimate of less than $90 million. However Rogge, 68, said he was confident attendances would be high.
"You need time for the organisation to be known, I am sure after the opening ceremony and definitely after the victory of Singapore in (the boy's) football (tournament on Thursday) against Zimbabwe 3-1 this will ignite the interest of the Singaporeans, no doubt about that."