Getting to Hat Yai — fly, train or coach compared
Hat Yai has no skytrain or city train like Bangkok, but it's a junction that connects every way in — read this before you decide how to travel.
If your time matters, flying is the answer. A direct Bangkok–Hat Yai flight takes about 1.5 hours in the air, with several departures a day from Don Muang (Thai AirAsia, Nok Air, Thai Lion Air) and Suvarnabhumi (Thai Airways), landing at Hat Yai (HDY) just ~12 km from town. Fares vary by date and how far ahead you book, from around ฿900 for a low-cost ticket booked well in advance up to roughly ฿2,500 at peak times or last minute. There are also some domestic routes from other Thai cities and the occasional regional flight linking Malaysia, but these come and go, so check the latest before you plan.
The Southern Line leaves Krung Thep Aphiwat Central Terminal (Bang Sue) — now the hub for all long-distance trains, not the old Hua Lamphong — and runs to Hat Yai in about 15–17 hours, with overnight services leaving in the evening and arriving in the morning. Fares cover a huge range by class, from around ฿270 for 3rd class up to roughly ฿1,300–1,500 for a 1st-class air-conditioned sleeper, with the popular 2nd-class air-con sleeper in the middle. Crucially, Hat Yai is a major rail junction for the south, with trains continuing down to Padang Besar to connect with the KTM network into Malaysia — so the train is a route that links Thailand and Malaysia in itself.
Air-conditioned coaches run Bangkok–Hat Yai from Sai Tai Mai (the Southern Bus Terminal) in about 12–13 hours, mostly overnight services leaving in the evening and arriving in the morning. Fares run around ฿700–1,200 depending on class and operator (from standard air-con up to VIP 24-seaters that recline a long way). The upside over flying is cost, plus seats that recline and a luggage hold underneath for big bags. Within the south, frequent minivans and buses also connect Hat Yai with Songkhla, Trang, Satun, Nakhon Si Thammarat and other towns throughout the day.