The best price found from United States to Ko Samui is on January 10th, 2017, travelling with Singapore Airlines. See more options, compare prices and book: search flights.
Ko Samui’s airport is in the northeast of the island near Big Buddha Beach. Bangkok Airways (www.bangkokair.com) operates flights roughly every 30 minutes between Samui and Bangkok’s Suvarnabhumi International Airport (50 minutes). Bangkok Airways also flies direct from Samui to Phuket, Pattaya, Chiang Mai, Singapore, Kuala Lumpur, Hong Kong and other cities in Southeast Asia. Firefly (www.fireflyz.com.my) operates direct flights from Ko Samui to Kuala Lumpur’s Subang airport and has three flights per week to Penang.
There is a Bangkok Airways Office in Hat Chaweng and another at the airport. The first (at 6am) and last (10pm) flights of the day are always the cheapest.
During the high season, make your flight reservations far in advance as seats often sell out. If the Samui flights are full, try flying into Surat Thani from Bangkok and taking the short ferry ride to Samui instead. Flights to Surat Thani are generally cheaper than a direct flight to the island, although they are much more of a hassle.