The nearest airports are Krabi, Trang and Phuket. Krabi and Trang have direct road and boat connections to Ko Lanta, and are the best options if you're only visiting Ko Lanta. Flying into Phuket is a better option if you're intending to spend time in Phuket and nearby islands, or, since Phuket has many more international flights, if you don't want to have to organize a domestic flight to Krabi or Trang from Bangkok. As an alternative to Bangkok, there are daily flights to Krabi directly to and from Singapore, as well as Kuala Lumpur.
There is scheduled van service from Krabi Airport taking roughly 2.5 hours, 250 baht if prearranged and 400-500 baht if arranging it at the airport (2016). When going back to the airport from the island, van can be booked via any tourist office for 250-300 baht, departs every round hour in the morning.
Private vans and taxis can be chartered to Ko Lanta for about 2,000 baht per vehicle (2,500 baht if you are going to the south end of Ko Lanta).
Air Asia and Nok Air have a special “Island Transfer” offering that includes a flight from Bangkok to Krabi, surface transport to the port, and a ferry to Ko Lanta. It can all be booked at their websites for additional price: Air Asia 470 baht, Nok Air 900 baht (2016).
Alternative to passenger van is an express transfer - the quickest albeit much more expensive way to get from Krabi Airport (2,045 baht per person) and Phuket Airport (3,350 Baht per person) to Ko Lanta. It is a combination of minivan and speedboat travel. If you arrive early you will not have to wait for the ferry and if you arrive late at these airports you can still arrive on Ko Lanta the same day. From Krabi airport a 45 minute air conditioned minivan to the first car ferry port. You then go on board the speedboat which then takes you on a stunning boat ride across the water along the coastline of Ko Lanta. The journey takes around 15 minutes depending on weather and conditions. You will arrive directly in Saladan (alternately written as Sala Dan) on Ko Lanta, where you are then transferred to your hotel by car. That means the total journey time should be 1.5 to 2 hours. This eliminates the waiting time at the car ferry and also if you are going from Ko Lanta to one of these airports allows you more time to enjoy your visit.
There is a minivan service that runs between Krabi Town and Ko Lanta, However it must be booked in advance through your hotel or someone local, the cost is 400 baht per person. Book early as it fills up quickly. It will pickup and drop off at the airport. You should factor in 3-4 hours to get from Ko Lanta to the airport, since the minivan will pickup and drop off other people along the way.
Vans going to Ao Nang cost 450 baht (2016), 3 hours, number of vans greatly varies during a year.
The distance from Bangkok to Krabi is approx 950 km or about 12 hr by car.
Ko Lanta does not have roads connecting it directly to the mainland, but is served by car ferries. Take Rte 4206 off Hwy 4 about 20 km southeast of Krabi airport. Drive to the end of the road, where there is a car ferry from Baan Hua Hin to Ko Lanta Noi. From the pier here, turn right and follow the "ferry" signs to the second car ferry to Ko Lanta Yai. Ferries operate 07:00-22:00.
There are plenty of car taxi and minivan taxi services from Krabi and the nearby airport. A seat in a ten-person minivan from the airport to Ko Lanta costs about 300 baht. These minivans usually don't have much room for luggage (although they can usually find room for one or two large suitcases together with backpacks for the rest of the passengers) so if you're not travelling light you might need to get a private taxi. This is what the dive masters do. A private minivan taxi will usually be quoted as 2,500 baht. It's possible to bargain a few hundred baht off this price but not much more or the tolls will consume too much of the price. Car taxis cost about the same.
When travelling to/from Ko Lanta in the afternoon by road, allow 2–3 hours for the journey as the queues for the vehicle ferries can be lengthy. The passenger ferry which leaves Ko Lanta pier (high season) at 08:00 and arrives at Krabi pier at 10:00 is quicker.
Private companies on Ko Lanta operate boat services to many destinations.
All ferries can be booked on-line or at any tourist agent.
Ferry services run from Krabi Town, Ao Nang, and from Phuket via Ko Phi Phi to Ko Lanta Yai's 1 Saladan pier. During high season, there are sometimes direct ferries as well. Ferry services are subject to weather and to demand: many ferries have limited room for luggage.
All above routes operate only during high season, while during low season only 1-2 daily ferries to Ko Phi Phi remain.
The nearest train station to Ko Lanta is in Trang province just south of Krabi. From there, there are trains to and from Bangkok.