Which developed countries in the world speak English

English is the first language in the following countries and territories:

Britain, the United States, Australia, the Bahamas, Ireland, Barbados, Bermuda, Guyana, Jamaica, New Zealand, St. Christopher and Nevis, and Trinidad and Tobago. There are currently about 300 million people in the world who speak English as a first (native) language.

English is the lingua franca in the following countries and territories:

Hong Kong (together with Cantonese), Canada (together with French), Dominica, St. Lucia and St. Vincent and the Grenadines (together with French), Micronesia (Federated States of), Ireland (together with Irish), Liberia (together with African languages), Singapore (together with Mandarin), Malaysia (with Chinese and Malay) and South Africa (with Afrikaans and other African languages). Approximately 250 million people speak it as a second language (i.e. it is not their mother tongue but is the lingua franca of the country in which it is spoken).