* Tanzania: Swahili is the national language of Tanzania, widely spoken and used in government, education, and media.
* Kenya: Swahili is one of the official languages of Kenya, alongside English. It is used in government, education, and commerce.
* Uganda: Swahili is one of the official languages of Uganda, alongside English and Luganda. It is commonly used in education, commerce, and among different ethnic groups.
* Rwanda: Swahili is a widely spoken language in Rwanda, though not an official language. It is used in education, commerce, and government.
* Burundi: Swahili is an official language of Burundi alongside Kirundi and French. It is used in education, commerce, and government.
* Democratic Republic of Congo (DRC): Swahili is a widely spoken language in the DRC, particularly in the eastern regions. It is considered a lingua franca for inter-ethnic communication.
* South Sudan: While not officially declared, Swahili is widely spoken in South Sudan, particularly in the eastern regions bordering Kenya and Uganda.
It's important to note that Swahili is also spoken in other parts of East and Central Africa, but it's not an official language in those countries. It serves as a lingua franca in various communities.