If you want a cheap flight from Cairns to Singapore, you've got two airlines to choose from.
Make sure you use the search options above to search for flights to other airports in Singapore, not just Singapore Changi International Airport. The more options you look at, the better your chance of finding a cheap deal. Just so you know, the flight typically takes 11 hrs 20 mins.
During this peak season, accommodation prices often increase too, so it's best to book early. Or you could keep your fingers crossed and hold out for a last-minute deal.