BankMuscat, Oman's largest bank based on total assets, was established as Oman Overseas Trust Bank in 1982 and has gone through four mergers and acquisitions to reach its current state and size. The first move occurred in 1993 when it merged with Al Bank Al Ahli Al Omani, an older competitor founded in 1976. In 1999, BankMuscat merged with Commercial Bank of Oman. In 2001, a third merger with Industrial Bank of Oman was implemented. In 2002, BankMuscat went regional with the acquisition of the Bahrain operations of ABN Amro, which included a full commercial branch in Manama and an offshore banking unit. In September 2004, it was announced that BankMuscat is planning to merge with yet another bank - National Bank of Oman, however, merger talks were called off and the Bank has been focusing since on expanding its operations beyond Oman with plans to enter Saudi Arabia, UAE, Kuwait, and Qatar, in addition to its existing operations in Bahrain.

The bank is currently active in the fields of retail and private banking, corporate, investment banking, and asset management services. It is a market leader in the retail sector with a 36.9% market share of customer deposits in Oman as of 2004 year end. BankMuscat has a license to operate in Saudi and has indicated that it plans to open 15 branches in the first five years of its Saudi operations. In addition to a representative office in the UAE, BankMuscat obtained a license for a trade finance company. The company is a joint venture between BankMuscat and Istithmar, an investment arm for the UAE government. BankMuscat also has a strategic stake in Centurion Bank, a private sector bank in India that has a network of 90 branches across 45 Indian cities. Centurion Bank merged with Bank of Punjab in 2005, giving BankMuscat a 25.34% post-merger share. BankMuscat also was a founding partner in Oman Investment CorporationOman Investment Corporation in 2005. In addition, it has recently set up BankMuscat International (BMI)BankMuscat International (BMI) an independent Banking entity that will be focused on becoming a GCC regional bank.

BankMuscat won multiple awards, including the 'Bank of the Year' for five consecutive years to 2005 from The Banker magazine (Financial Times), the 'Best Consumer Bank for 2005' for the second year in Oman by the Global Finance , the JP Morgan Chase '2004 Quality Recognition Award', and the 'Best Place to Work in Oman' for the second time in 2005 by BusinessToday.

BankMuscat, was the first GCC banks to tap the international capital market with a USD 163 million dollar global depository receipts (GDRs) on the London Stock Exchange to increase its issued capital by 10%.