The spokeswoman for the Flyer said the stranded passengers were given water and food throughout their ordeal, handed to them by Singapore special services who climbed up and abseiled from the wheel.
Anna-Louise Allen, an Australian tourist who was trapped in one capsule, said: "We thought we were going to have to abseil out of the capsule. Of course we were getting fairly panicky about that."
Ten passengers were rescued using harnesses.
The power outage was the fourth at the Flyer, Steven Yeo, general manager of the attraction, said.
Standing at a height of 165 metres, the Flyer started operations in the city state in February and is 30 metres taller than the London Eye.
It has 28 bus-sized capsules attached to a circular frame 150 metres in diameter. Each capsule can accommodate 28 people.
Meta Hartono, an Indonesian visitor, said trapped passengers resorted to urinating in plastic bags while they were hanging in the air.
"I love Singapore but I don't think I'll come to the Flyer again," she said.