Can you sunbathe in a bikini on Sri Lankan public beaches?

Yes, lying out in a bikini is completely acceptable on popular tourist beaches in Sri Lanka, like Mirissa, Unawatuna, Arugam Bay, and Hiriketiya.

Sri Lanka is a modest country, but the seaside towns that live on visitors have more relaxed norms about beachwear. Still, topless sunbathing or being nude is strictly illegal, and it is culturally offensive anywhere on the island. Also, when you step out of the immediate sand to walk into town, visit local shops, or eat at inland restaurants, you should cover up with a dress, a sarong, or a T-shirt.