Ghanshyam Das Birla, an eminent Indian industrialist, during the Quit India movement of 1942, conceived the idea of organizing a commercial bank with Indian capital and management, and the United Commercial Bank Limited was incorporated to give shape to that idea. The bank was started with Kolkata as its head office with an issued capital of ₹2 crores and a paid-up capital of ₹1 crore. Birla was its chairman and the Board of Directors included eminent personalities of India drawn from many fields. The bank opened 14 branches simultaneously across India.
After World War II, United Commercial Bank opened several overseas branches. The first, in 1947, was in Rangoon. Branches in Singapore (1951), Hong Kong (March 1952), London (1953), and Malaysia followed. In 1963 the Burmese Government nationalized United Commercial Bank's three branches there, which became People's Bank No. 6. On 15 September 1967, Jalpaiguri Banking and Trading Corporation (JBTC) which had been established in Jalpaiguri in 1887 (or 1889; accounts differ), made a voluntary transfer of its assets and liabilities to United Commercial Bank. JTBC had only one office and specialized in lending against mortgages on tea gardens. The Government of India nationalized United Commercial Bank on 19 July 1969. 
During FY 2013-14, its total business was ₹ 4.55 lakh crore. Based on 2014 data, it is ranked 1860 on Forbes Global 2000 List. UCO Bank was ranked 294th among India's most trusted brands according to the Brand Trust Report 2014, a study conducted by Trust Research Advisory. It was a rise of 796 ranks considering it was listed at the 1090th position among India's most trusted brands in the Brand trust Report 2013. As of 6 January 2017 the bank had 4,000 plus service units 49 zonal offices spread all over India. It also has two overseas branches in Singapore and Hong Kong. UCO Bank's headquarters is on BTM Sarani, Kolkata.