Air New Zealand has the most flights (all from Auckland, but with good connections from Australia and NZ). Samoa Airways flies from Auckland and Sydney, Virgin flies from Sydney and Melbourne (with good Australia connections). Fiji Airways flies from various Australia and NZ locations via Nadi and direct from Hawaii. Booking flights directly using the airlines booking sites tend to provide the best value deals. For travel originating outside New Zealand and Australia your travel agent or specialised flight aggregator site may provide a better deal.
When planning flights consider the total flight duration and timing. There are flights from almost every city in NZ that will get you to or from Samoa in a day at reasonably civilised hours and without the extra cost of a night in Auckland. The direct flights from Sydney and Melbourne with Virgin tend to run at odd hours meaning that you will arrive very sleep deprived so its worth considering the options via Auckland. Samoa Airways afternoon flights to Sydney are well timed, the other way is not so civilised.
As at October 2021 flight schedules continue to be suspended due to covid. We will update this page as regular flights resume.