BOC was founded in 1939, with Sir Ernest de Silva as its first chairman. At the time, Ceylon was a British colony and the then governor Sir Andrew Caldecott ceremoniously opened the bank on 1st August. The English government introduced the banking arm for for its government-oriented businesses. Two years later, in 1941, BOC started to expand beyond the city of Colombo. It opened its first branch in Kandy. Subsequently, BOC added branches in major cities such as Galle, Jaffna, Kurunegala, Batticaloa, Trincomalee, Badulla and Panadura. 