The ITU Telecommunication Standardization Sector (ITU-T) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU); it coordinates standards for telecommunications.

The standardization work of ITU dates back to 1865, with the birth of the International Telegraph Union. It became a United Nations specialized agency in 1947, and the International Telegraph and Telephone Consultative Committee (CCITT, from French: Comité Consultatif International Téléphonique et Télégraphique) was created in 1956. It was renamed ITU-T in 1993.

ITU has been an intergovernmental public-private partnership organization since its inception and now has a membership of 191 countries (Member States) and over 700 public and private sector companies as well as international and regional telecommunication entities, known as Sector Members and Associates, which undertake most of the work of the Sector.

ITU-T has a permanent secretariat, the Telecommunication Standardization Bureau (TSB), based at the ITU HQ in Geneva, Switzerland. The elected Director of the Bureau is Malcolm Johnson of the UK. Johnson was elected by the ITU Membership to the directorship for a 4-year term in November 2006 and was reelected for a second term starting January 2011.