ICO or Ico may refer to:

• ICO (file format), a file format used for icon images in Microsoft Windows
• Index of Central Obesity, a measurement of abdominal obesity
• Indian Computing Olympiad, an annual computer programming competition
• Initial coin offering, a funding process involving a new cryptocurrency
• Intermediate circular orbit, a type of satellite orbit

• ICO Global Communications, a mobile satellite services company based in Reston, Virginia, US
• Catalan Ornithological Institute (Institut Català d'Ornitologia), a non-profit for the study of birds in Catalonia
• Illinois College of Optometry, a private college in Chicago, Illinois, US
• Information Commissioner's Office, a UK regulator
• Institute of Contemporary Observation, a Chinese non-governmental organization
• International Coffee Organization, a group for enhancing cooperation between nations dealing in coffee
• International Commission for Optics, a commission for knowledge in optics
• International Communist Opposition, a group of critics of the Communist movement
• International Council of Ophthalmology, a body serving associations of ophthalmologists
• Instituto de Crédito Oficial, a Spanish state-owned development bank
• Irish Chamber Orchestra, a chamber orchestra in Ireland
• Irish College of Ophthalmologists, the national body for ophthalmology training in Ireland
• Israel Chamber Orchestra, a chamber orchestra in Israel

• Cocos (Keeling) Islands (ITU code: ICO), an Australian territory in the Indian Ocean
• Icó, a town in Ceará, Brazil

• Ico, a 2001 PS2 action-adventure video game
• Ico, el caballito valiente, a 1983 Argentine animated film
• Ico Hitrec (1911–1946), Croatian football player

• IKO (disambiguation)
• All pages with titles beginning with ICO
• All pages with titles containing ICO