The Bureau of Special Investigation (Burmese: အထူးစုံစမ်းစစ်ဆေးရေးဦးစီးဌာန; BSI) is the domestic intelligence and security service of the Republic of the Union of Myanmar.

BSI is a department of the Ministry of Home Affairs (Myanmar).

[1] The bureau has authority to investigate legal offences, including financial crimes, such as inappropriate trading, tax evasion, and government officer corruption allegations.

In 1951, the Special Investigation Administrative Board was formed under the direct supervision of the Prime Minister with 315 number of staff in accordance with "The Bureau of Special Investigation Act".

[2] In 1963, it was renamed as Bureau of Special Investigation under the administration of the Ministry of Home Affairs.