Smoke coming through the air vents set off a fire alarm, prompting evacuation of the terminal, airport officials said in an earlier message on social media site Facebook.
"Passengers on flights departing from T2 this evening should expect significant delays. We will advise when operations resume," they said.
The fire has been extinguished, the Singapore Civil Defence Force said on its Facebook page. Police earlier said they had been notified of a fire in the terminal's departures hall.
(Reporting by Aradhana Aravindan; Editing by Clarence Fernandez)