List of territorial entities where English is an official language

The following is a list of territories where English is an official language. As of 2019, there were 55 sovereign states and 27 non-sovereign states where English was an official language.
Overview.
British Empire.
Most countries where English is a prominent or official language are former colonies of the British Empire. Notable exceptions include Rwanda, which was a former Belgian colony, and Eritrea, which was an Italian colony where the British Empire controlled it only in World War II and shortly after (19411952).
English is the sole official language of the Commonwealth of Nations and the Commonwealth Games. 
International organizations.
English is one of the official languages of the United Nations, the European Union and the International Olympic Committee.
United States.
Although English is not classified as an official language in the United States. Instead, many states and regions within the U.S. do have English as an official language.
India.
India's linguistic picture is complex. According to the Constitution of India, "Hindi in the Devanagari script" is the official language of the union; and English the 'subsidiary official language'; however, English must be used for the official texts of all federal laws and Supreme Court decisions (with Hindi). It is one of the two languages of the Indian Parliament. English is taught in schools. The quality and effectiveness of the teaching is very varied. English is used almost exclusively for higher education.
Pakistan.
The situation of Pakistan is also complex. While the national language is Urdu, English is an official language and used in business, government and law.
Country subdivisions.
In these country subdivisions, English has "de jure" official status, but English is not official in their relevant countries at the national level.