The Commonwealth Telecommunications Organisation (CTO) traces to the British Empire's Pacific Cable Board in 1901, though in its current form, was created by international treaty, the Commonwealth Telegraphs Agreement between Commonwealth nations signed in London on 11 May 1948.

The CTO connects government and non-government entities to enhance cooperation in information and communication technology (ICT).

To oversee the completion of the All Red Line telegraph system interlinking the British Empire, the Pacific Cable Board was formed in 1901.

In the final years of the British Empire, with a number of states federated or close to independence, a treaty with clearer financial divisions, responsibilities, and governance was established that would eventually replace the Pacific Cable Board. The Commonwealth Telegraph Agreement was signed between Commonwealth nations in London, 1948 that formed the Commonwealth Telecommunications Organisation.

The government members of the CTO are:

ICT sector members include Avanti Communications, British Telecom, Facebook, Huawei, Intelsat, PwC London, Safaricom, and Vodafone.