Koh Lanta is most easily reached from Krabi. During the dry season (November to April), regular ferries run from Krabi Town and Krabi's Ao Nang pier to Ko Lanta, taking 1.5–2.5 hours depending on the route. The most scenic approach is via a speedboat that stops at Ko Phi Phi en route — a 2-hour trip. High-season services are frequent; in the shoulder months, check schedules carefully as frequency drops.
From Koh Lanta you can also pick up speedboat connections to Koh Phi Phi, Koh Ngai, and other Andaman islands. A vehicle ferry runs year-round from the mainland town of Hua Hin to the northern tip of the island, crossing two short straits. Most guesthouses and resorts can arrange transfers from Krabi Airport, which is the most convenient access point for international arrivals.
During the low season (May to October), the ferry service becomes irregular and some routes close entirely. Getting to or from the island during monsoon season typically requires a minibus connection via the mainland vehicle ferry.