Kuala Lumpur to Bangkok

About a dozen nonstop flights a day connect the two cities, slightly more of them to Don Mueang than to Suvarnabhumi. AirAsia flies from KLIA's Terminal 2, also called klia2, to Don Mueang several times a day, from 06:35 in the morning to 19:40 in the evening, and Thai AirAsia adds a late-morning flight. Batik Air flies to Don Mueang from Subang, the old city airport, in the late afternoon. Malaysia Airlines and Thai Airways fly from Terminal 1 to Suvarnabhumi, and Thai Vietjet has an evening flight to Suvarnabhumi too. Booking sites also sell a lot of one-stop tickets through Singapore that take most of a day, so filter for nonstop.

The flight takes 2 hours 15 to 2 hours 20, but Thailand is an hour behind Malaysia, so on the clock it looks like 75 to 80 minutes. AirAsia asks you to be at the airport two to three hours before an international flight. From KL Sentral, the KLIA Ekspres reaches Terminal 1 in 28 minutes for RM55, runs every 20 minutes, and carries on to Terminal 2 three minutes later. Check which terminal your ticket says before you get off.

Pick the airport by what you're doing next. Don Mueang suits the old city, Khao San Road and anyone catching a train north or south, because the SRT Red Line runs from a skywalk outside the terminal to Krung Thep Aphiwat, the long-distance station, for ฿33. The A1 bus goes to BTS Mo Chit for ฿30, and a taxi into town is about ฿250–400 plus tolls. It's also where Thai AirAsia and Thai Lion Air's domestic flights leave from, if you're flying on to Chiang Mai or an island.

Suvarnabhumi suits Sukhumvit, Silom and the riverside hotels, and anyone connecting to a long-haul flight. The Airport Rail Link takes 26 minutes to Phaya Thai for ฿45, and a metered taxi is about ฿400–600 with the surcharge and tolls. The two airports are 60 to 90 minutes apart across town, so if you're connecting to another flight, land at the airport it leaves from. Our Bangkok airport guide has every option from both.

AirAsia's cheapest fares include 7 kg of hand luggage and no checked bag, and that 7 kg covers your cabin bag and your personal item together, so a laptop bag counts. The cabin bag is limited to 56 x 36 x 23 cm including wheels and handles, and the small bag to 40 x 30 x 10 cm. Anything over 7 kg has to go in the hold, so if you're carrying more, add a checked bag when you book. Thai Vietjet's basic Eco fare also comes with 7 kg of carry-on and, on most routes, no checked bag. Read the baggage line on the fare before you compare prices, because the cheapest fare on the screen is often the one with nothing in the hold.

There's no direct train, so the trip is two trains on two tickets. The first is a KTM ETS from KL Sentral to Padang Besar, the Malaysian border station. Two morning trains connect with the Thai sleeper, the 07:20 Platinum, which arrives at 12:41, and the 09:55 Platinum, which arrives at 15:16. The 09:55 is the one I'd book, and the 07:20 is the safe choice if you want a few hours of slack. The 12:16 Gold arrives at 17:53, seven minutes before the sleeper leaves, which is too close with two immigration checks in between. Seat61 lists the KL Sentral to Padang Besar fare at RM79 in Gold and RM116 in Platinum standard class, and KTMB's fares change by train and date, so expect more on busy days.

Book the ETS on KTMB's website or the KTMB Mobile app. Seat61 reports busier ETS trains filling a day ahead, and KTMB's sales open on a schedule that varies, so book as soon as your date is on sale. KTMB has changed the ETS timetable several times in 2026, so check the current times on KTMB before you book the Thai train.

Special Express No. 46 leaves Padang Besar at 17:00 Thai time, which is 18:00 on Malaysian clocks, and Thai timetables and booking sites show the Thai time. It reaches Hat Yai at 17:46, where it's joined to No. 38 from Sungai Kolok and picks up that train's dining car, then runs overnight up the peninsula, through Surat Thani at 22:47 and Hua Hin at 05:12, to Krung Thep Aphiwat in Bangkok at 09:05. It doesn't stop at Don Mueang. The MRT Blue Line runs from under the station into the city.

From Padang Besar it carries two second-class air-conditioned sleeper cars, with upper and lower berths that each have a privacy curtain. SRT's fares are ฿848 for an upper berth and ฿918 for a lower one, and the lower berth has the window and sways less, so it's the one I'd book. Third-class seats are added only as far as Hat Yai. Seat61 says the berths can sell out a week or two ahead, and by SRT's booking rules a ticket for the whole run should go on sale about 90 days before departure on the D-Ticket site. Passengers report the train running an hour or more late at times, so don't plan anything tight in Bangkok that morning.

There's no bus from Kuala Lumpur all the way to Bangkok, but plenty go to Hat Yai, the big city on the Thai side. They leave from TBS, Kuala Lumpur's southern bus terminal, mostly between 08:00 and 10:00 in the morning or between 20:30 and 01:30 at night, take 8 to 14 hours and cost about ฿500–800 on 12Go. Companies include Alisan, City Express, Inter Top Express, Suasana Tony Coach and Super Nice Express. The bus crosses at Bukit Kayu Hitam and Sadao, where everyone gets off for Malaysian exit and Thai entry and takes their bags through for scanning. Stay with the group and note the bus number, because one passenger reported the bus pulling away while she was still at immigration.

A night bus gets you to Hat Yai in the morning, and the evening trains to Bangkok leave after 16:00. The one I'd take is Special Express No. 32, which leaves Hat Yai at 17:45 and reaches Krung Thep Aphiwat at 08:10, with newer sleeper cars and a dining car. A second-class berth is ฿1,005–1,105, and first class ฿1,594–1,794 a berth or ฿2,594 for a cabin to yourself. No. 46 also calls at Hat Yai at 18:05. Overnight buses to Bangkok leave Hat Yai between 15:30 and 18:00 too, for about ฿860–1,020.

This is also the route I'd point UK travelers to. The UK Foreign Office advises against all but essential travel on the Hat Yai to Padang Besar train line, and travel against its advice can invalidate a UK travel insurance policy. Its advice doesn't name the Bukit Kayu Hitam and Sadao road crossing or Hat Yai itself. The US State Department's increased-caution warning covers Yala, Pattani and Narathiwat, not this route. KTMB also runs MySawasdee, a charter train from KL Sentral at 22:50 to Hat Yai at 08:50 Thai time on selected dates, for RM95 a seat or RM109–119 a berth, but it uses the same border railway.

Most Western passports get 30 days on arrival without a visa, and you need a Thailand Digital Arrival Card for every entry, by air or by land. Officers can ask for an onward ticket out of Thailand within your permitted stay. If you're coming overland after time in Malaysia, remember the two-a-year cap on land entries on the exemption, which doesn't apply to arrivals by air. Our Thailand visa guide covers the rules by nationality, and our TDAC guide walks through the form.

Going back, Special Express No. 45 leaves Krung Thep Aphiwat at 16:10 and reaches Padang Besar at 08:05 Thai time, 09:05 in Malaysia, for ฿870 an upper berth or ฿960 a lower one. You clear Thai exit and Malaysian entry in the station and take an ETS south, just under five hours to KL Sentral. Malaysia asks visitors to file its Digital Arrival Card, the MDAC, in the three days before arriving, and Singapore citizens are exempt. The flights back leave from the same two airports, AirAsia, Thai AirAsia and Batik Air from Don Mueang and Malaysia Airlines, Thai Airways and Thai Vietjet from Suvarnabhumi.