The Postal, Telegraph and Telephone International (PTTI) was a global union federation bringing together unions of communications workers worldwide.

While a meeting of unions of communication workers was held in Paris in 1911, no lasting organisation was established until 1920, when the PTTI was founded at a meeting in Milan. Initially, the federation consisted entirely of European unions, but after World War II, it expanded worldwide, and by 1994 had four million members from every continent except Antarctica.^[1]

By 1997, new forms of communication had grown in importance, and the federation renamed itself as the Communications International.^[1] At the end of 1999, it merged with the International Federation of Commercial, Clerical, Professional and Technical Employees, the International Graphical Federation, and the Media and Entertainment International, to form Union Network International.^[2]

In 1998, the following unions were affiliated to the PTTI:^[3]