La-ngu is a district (amphoe) of Satun province, southern Thailand. La-ngu's port, Pak Bara, is the ferry port year-round for boats going to most of the islands in Tarutao Marine National Park, which includes Ko Lipe. It is now the proposed site of Thailand's deep-seaport on the Andaman Sea.

An amphoe —usually translated as "district"—is the second level administrative subdivision of Thailand. Groups of amphoe or districts make up the provinces, and are analogous to counties. The chief district officer is Nai Amphoe. Amphoe are divided into tambons,, or sub-districts.