United Overseas Bank

On 6 August 1935, Sarawak-born businessman Wee Kheng Chiang, together with six other partners, established the bank with a paid-up capital of S$1 million. The bank was originally incorporated as United Chinese Bank (UCB) and served the mainly Hokkien Chinese community in Singapore. Wee, being the largest shareholder, became its first chairman. In October 1935, UCB opened for business in the three-story Bonham Building. On 23 January 1965, UCB changed its name to United Overseas Bank (Chinese name unchanged) to avoid duplication with another United Chinese Bank in Hong Kong (simplified Chinese: 中国联合银行; traditional Chinese: 中國聯合銀行), and opened its first overseas branch in Hong Kong.

In 1970, UOB was listed on the Joint Stock Exchange of Singapore and Malaysia. At the time, the stock exchange had an office in both Singapore and Kuala Lumpur. After it was publicly listed, the bank went through a series of targeted acquisitions. The bank first acquired the controlling stake of Chung Khiaw Bank in 1971, which expanded its domestic presence and also gave the bank offices in Malaysia and Hong Kong. A new logo for both United Overseas Bank and Chung Khiaw Bank was launched in January 1972.

In 1973, UOB acquired Lee Wah Bank, which was originally founded in 1920 by Eu Tong Sen with Cheong Yoke Choy as one of its co-founders and original directors, provided services in Malaysia and Singapore. In that same year, the bank built a new 30-storey office tower in place of the Bonham Building, which was named the UOB Building (now known as UOB Plaza Two). The company continued with acquisitions, with Far Eastern Bank in 1984, Westmont Bank (now known as UOB Philippines) and Radanasin Bank (now known as United Overseas Bank (Thai) Public Company Limited) in 1999.

In September 2001, UOB acquired Overseas Union Bank, then Singapore's fourth largest local bank, in a deal worth S$10 billion.

In 2002, UOB started expanding into the Chinese market by opening a new full-service branch office in Shanghai and upgrading of its Beijing office to a full-service branch.

On 16 January 2019, UOB was listed in the Bloomberg Gender-Equality Index (GEI) for the first time in recognition of gender equality.

On 14 January 2022, UOB purchased Citigroup's consumer banking franchises in Indonesia, Malaysia, Thailand and Vietnam for about S$5 billion.

International operations

UOB has branches and offices located across Asia Pacific, North America and Western Europe, with most of their operations located in Southeast Asian countries such as Brunei, Malaysia, Indonesia, Myanmar, Philippines, Thailand and Vietnam.

Australia

Headquartered in the UOB Building in Sydney, UOB Australia opened its first branch in MLC Centre as a merchant bank in 1986 to emphasize trade and financing between Australia and Asia. The bank now has offices in Melbourne and Brisbane, in addition to the branch in Sydney and currently offers merchant bank services comprising current accounts, deposits, lending, asset finance, trade finance, structured finance, cash management, and cross-border payments.

Brunei

UOB's operations in Brunei started in 1974, under Overseas Union Bank (OUB). When UOB acquired the Overseas Union Bank in January 2002, the operations of the branches in Brunei was handed over to UOB. On 1 October 2005, the bank relocated its branch office in Bandar Seri Begawan.

In 2015, UOB sold its retail banking business to Baiduri Bank Berhad for S$65.044 million. The bank currently provides a full range of commercial and corporate banking services through the branch located in the country. It also operates UOB Asset Management in Brunei, which offers investment management expertise to individuals, institutions and corporations.

Controversies

1Malaysia Development Berhad scandal

In May 2017, the Monetary Authority of Singapore (MAS) fined UOB a total of S$900,000 for several breaches of anti-money laundering rules and control lapses in transactions related to Malaysia’s scandal-ridden sovereign wealth fund 1Malaysia Development Berhad (1MDB). These include weaknesses in conducting due diligence on customers and inadequate scrutiny of customers’ transactions and activities.

RBI fine due to compliance lapses

On 1 October 2019, UOB was fined INR₹10 million by the Reserve Bank of India (RBI) for compliance failures based on deficiencies in regulatory compliance.

Money laundering and business conduct compliance failures fine

On 31 August 2022, the stockbroking arm of UOB – UOB Kay Hian Private Limited which is an associated company of UOB, was fined S$375,000 for failing to comply with business conduct requirements under the Securities and Futures (Licensing and Conduct of Business) Regulations, as well as anti-money laundering and countering the financing of terrorism requirements listed by the Monetary Authority of Singapore (MAS).

S$3 billion money laundering case in 2023

On 4 July 2025, UOB and UOB Kay Hian (UOBKH) were each handed S$5.6 million and S$2.85 million respectively in penalties by the Monetary Authority of Singapore (MAS) for flouting anti-money laundering controls related to the 2023 money laundering case involving more than S$3 billion in assets. The 10 criminals were reportedly part of the Fujian gang, an organised crime syndicate originally from China’s Fujian province who washed more than S$3 billion in illicit funds and using multiple passports to avoid detection. All have been jailed, deported after serving their sentences and barred from re-entering Singapore.

UOB and UOBKH did not adequately establish and corroborate the source of wealth of customers who posed a higher risk of money laundering, even though there were significant discrepancies in the documents they had provided. UOB and UOBKH also did not adequately investigate suspicious transactions flagged by their own systems and fell short in following up on suspicious transaction reports filed against their customers. The institutions failed to take adequate and timely risk mitigation measures, such as enhanced monitoring and reviewing the customers’ risk classification. In additional, UOBKH failed to implement adequate policies or processes for rating money laundering risks presented by some of their customers. This led to mis-rating of the risks and affected its ability to address higher money laundering risks presented by several persons of interest.