Carex capillacea, common name yellowleaf sedge in Tasmania,[4] is a species of sedge (in the Cyperaceae family) found in Assam, the far east of Russia, New Guinea, south east Australia, New Zealand,[2] Malesia, China, Japan and India.

[7] In New Zealand it is found on the North Island on the Waimarino Plain, and the Moawhango and in the South Island from Nelson and Marlborough south to the lakes of Te Anau, Manapouri, Hauroko and east to Lumsden.

[5] Assessments under the New Zealand Threat Classification System (NZTCS), declared it to be "At Risk – Naturally Uncommon" (NU) in 2013, and in 2017 to be "Threatened – Nationally Vulnerable" (NV).

[4] Carex capillacea was first described in 1858 by Francis Boott from specimens collected in the temperate eastern Himalayas at 10,000 to 12,000 feet (3,000 to 3,700 m) by Joseph Dalton Hooker in Sikkim and by William Griffith in Bhutan.

[2][3] The specific epithet, capillacea, derives from the Latin capillus "hair" or "thread", and thus describes the plant as being thread-like.