The account will move from incumbent Weber Shandwick, but will not include the airline's budget carrier Tiger Airways.
With the win, Liquid Ideas will be responsible for actively publicising and promoting the Singapore Airlines brand, including its various products and services. It will also support the airline's corporate communications, as well as managing events and activations in Australia.
"We couldn't be more excited to be working with what we think is quite simply the world's greatest airline brand," remarked Liquid Ideas founder and director Stuart Gregor.
The agency also handles clients such as Kellogg's, Toby's Estate, De'Longhi, Stella Artois, Pol Roger Champagne and the National Wine Show of Australia.