爪哇海沟也称巽他海沟，是位于印度洋东北的一条长2,600公里的海沟，其最深处达7,725米（南纬10°19'，东经109°58'，离日惹约320千米）。长时间中它被认作是印度洋中最深的海沟。但后来的考察数据证明位于澳洲柏斯西南偏西1,125公里之蒂阿曼蒂那海沟（Diamantina Trench）还要深（8,047米）。因此爪哇海沟是印度洋第二深的海沟。

爪哇海沟是东部的缅甸板块和巽他板块与西部的印度板块的接缝处。这三个板块在这里的变形以及隐没带造成了2004年印度洋大地震和2004年12月26日爆发的致命海啸。

The Sunda Trench, earlier known as, and sometimes still indicated as the Java Trench, is located in the northeastern Indian Ocean, with a length of 3,200 kilometres (2,000 mi). The maximum depth of 7,725 metres (25,344 ft) (at 10°19'S, 109°58'E, about 320 km south of Yogyakarta), is the deepest point in the Indian Ocean. The trench stretches from the Lesser Sunda Islands past Java, around the southern coast of Sumatra on to the Andaman Islands, and forms the boundary between Indo-Australian Plate and Eurasian plate (more specifically, Sunda Plate). The trench is considered to be part of the Pacific Ring of Fire as well as one of a ring of oceanic trenches around the northern edges of the Australian Plate.