Tumaguin (variously Tamaguin, Tomaquin, or Tumaguin Islet) is a small, uninhabited island in the Visayan Sea.

Along with nearby Sicogon Island, it is part of Carles, Iloilo.

[1] The island is 52 metres (171 ft) above sea level.

[2] There is a four fathom patch of deep water a little over 4 kilometres (2.5 mi) from the island.

[3] Tumaguin Island is accessible from barangay Buaya in Sicogon by boat, or by foot during low tide.