Neduntheevu or Nedunthivu (Tamil: நெடுந்தீவு, romanized: Neṭuntīvu; Sinhala: ඩෙල්ෆ්ට්, romanized: Ḍelfṭ) (also known by its Dutch name Delft) is an island in the Palk Strait, northern Sri Lanka. This island is named as Delft in the Admiralty Chart unlike the other islands, whose names are Tamil. The island's area is 62 km and it is roughly oval-shaped. Its length is 11 km and its maximum width about 6 km.

Neduntheevu is a flat island surrounded by shallow waters and beaches of coral chunks and sand. It is home to a small population of Tamil people, mostly living in quiet compounds close to the northern coast. The vegetation is of a semi-arid tropical type, with palmyra palms, dry shrubs and grasses that grow on the pale grey porous coralline soil. Papayas and bananas grow close to the local people's homes. The water is slightly brackish, and it is taken from shallow wells using buckets made from palmyra palm leaves. A naval battle was fought off the coast of the island in 2008 during the Sri-Lankan Civil War. There are feral ponies on the island, descendants of forebears abandoned there in the Dutch period.

The island was named after the Dutch city of Delft by Rijckloff van Goens. He named the eight most important islands after Dutch cities.

In the north-western part of Delft Island, The remains of a Hindu temple built in the Chola style in the 10th or 11th century as well as the ruins of a Dutch colonial fort have been identified on the western coast of the island.

In 2013, marine archaeologists from the Maritime Archaeology Unit (MAU) of the Central Cultural Fund (CCF) discovered a few eroded coral slabs containing Tamil scripts. According to their early suggestions, these Tamil scripts belong to the 14-15 centuries. However, as another coral slab engraved in modern English scripts was discovered on the same site with same eroded conditions, it was later identified that all these inscriptions have not been engraved in the 14-15 centuries but in the recent past.

• Queen's Tower (Neduntheevu)

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  Growing Rock, observed to be accreting
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  Giant footprint, also known as Adam's or Shiva's footprint
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  Stable remains
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  Feral ponies
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  Pigeon house (dovecote), used by colonial powers
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  Baobab (Adansonia digitata), native to East Africa, introduced by Arabian sailors in 7th century.
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  Coral walls, a common sight
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  Ruins believed to be an ancient temple or Vedi Arasan fort.
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  The Manmade Coral Walls of Delft