About 3,500 mourners lined the streets where Mr Gately was raised in a send-off to the late Boyzone star.
The four remaining members of the band sang and spoke at the service which fans listened to through speakers, RTE reports.
During his eulogy, Ronan Keating said Steven Gately was now at peace.
450 invited guests are attending a funeral party in the Four Seasons Hotel, Ballsbridge.
