If by sleeping on the beach, you mean camping, the answer is yes - there are specific beaches in Hawaii where you can pitch your tent at night and spend the rest of the day along the shore. Research is key when determining if it is allowed to go camping on a specific public property or not. Here are some of the beaches where an overnight stay is possible: - Polihale State Park (Highway 50, Waimea, Hawaii) - Bellows Field Beach Park (Kalanianaole Highway, Waimanalo, Hawaii) - Malaekahana Beach Campground (Kamehameha Highway, Kahuku, Hawaii) - Anahola Beach Park (Anahola, Hawaii) - Hulopoe Beach Park (Lanai City, Hawaii) - Kea’au Beach Park (Farrington Highway Waianae, Hawaii) When sleeping on the beach, make sure to know how to protect yourself from any form of danger as, more often than not, open beaches also mean open opportunities for thieves and the like. Aside from this, you also have weather threats in the form of strong winds and heavy rains. Be sure to know these things ahead of time.