The Sulu Sea (Filipino: Dagat ng Sulu; Tausug: Dagat sin Sūg; Chavacano: Mar de Sulu; Cebuano: Dagat sa Sulu; Hiligaynon: Dagat sang Sulu; Karay-a: Dagat kang Sulu; Cuyonon: Dagat i'ang Sulu; Malay: Laut Sulu) is a body of water in the southwestern area of the Philippines, separated from the South China Sea in the northwest by Palawan and from the Celebes Sea in the southeast by the Sulu Archipelago. Borneo is found to the southwest and Visayas to the northeast.
Sulu Sea contains a number of islands. The Cuyo Islands and the Cagayan Islands are part of the province of Palawan whereas Mapun and the Turtle Islands are part of the province of Tawi-Tawi. Sulu Sea is also where the Tubbataha Reef National Marine Park, one of the World Heritage Sites is located.
It extends about 490 miles (790 kilometres) from north to south and 375 miles (604 kilometres) from east to west. Waves can stretch across 25 kilometres (16 miles) to 35 kilometres (22 miles). The sea is 4,400 metres (14,400 feet) deep but on its southern end Sulu Archipelago raises the sea floor to 100 metres (330 feet).
On the Northeast. The Southwest coast of Mindoro to Buruncan Point, its Southern extreme, thence a line through Semirara and Caluya Islands to Nasog Point () the Northwestern extreme of Panay, along the West and Southeast coast of that island to Tagubanhan Island (), thence a line to the Northern extreme of Negros and down the West coast to Siaton Point, its Southern extreme, thence across to Tagolo Point (), Mindanao.
On the Southeast. From Tagolo Point, down the West coast of Mindanao to the Southwest extremity thence to the North coast of Basilan Island (), through this island to its Southern extremity, thence a line to Bitinan Island () off the Eastern end of Jolo Island, through Jolo to a point in long. 121°04'E on its South coast, thence through Tapul and Lugus Islands and along the North coast of Tawi Tawi Island to Bongao Island off its Western end (), and from thence to Tanjong Labian, the Northeastern extreme of Borneo.
On the Southwest. The North coast of Borneo between Tanjong Labian and Tanjong Sempang Mangayau.
The Star Trek character Hikaru Sulu is named after the Sulu Sea. According to Sulu actor George Takei, "[Gene] Roddenberry's vision for Sulu was to represent all of Asia, being named for the Sulu Sea instead of using a country-specific name".