The company operates in Canada and Asia as "Manulife" and in the United States primarily through its John Hancock Financial division.

[4] As of December 2021, the company employed approximately 38,000 people and had 119,000 agents under contract, and has CA$1.4 trillion in assets under management and administration.

Manulife was incorporated as "The Manufacturers Life Insurance Company" by Act of Parliament on June 23, 1887, and was headed by Canada's prime minister, John A. Macdonald, and Ontario's lieutenant-governor, Alexander Campbell (there were no conflict-of-interest guidelines at the time and it was not unusual for public persons to be involved in private industry).

In 1988, Manulife opened a new five-storey office building at 500 King Street North in Waterloo to house its Canadian Division.

[22] In 2003, Manulife-Sinochem received approval for a branch office in Beijing, the first multiple-branch license granted to a foreign-invested joint venture life insurance company.

[21] On September 29, 2003, Manulife announced its intent to acquire the Boston-based insurance company John Hancock Financial (including a Canadian subsidiary, Maritime Life) for $10.4 billion in a stock-for-stock merger.

[23] The merged entity would initially be led by John Hancock's CEO David F. D'Alessandro, but he would step down in June 2004.

[34] In 2009, Donald Guloien, the chief investment officer, succeeded Dominic D'Alessandro as president and CEO of the company.

[38] In June 2015, Manulife-Sinochem became the first foreign invested joint-venture life insurance company in China authorized to sell mutual funds.

Manulife paid the $1.15 million penalty[44] levied on its bank subsidiary for failing to disclose information on suspicious transactions.

The Financial Transactions and Reports Analysis Centre of Canada (FINTRAC) imposed the penalty on Manulife Bank of Canada, alleging that the bank failed to file a suspicious transaction report, which was designed under the Proceeds of Crime (Money laundering) and Terrorist Financing Act to detect criminal activity.

[45] In an interview with Go Public, a Manulife insider claimed there were major privacy issues within the company's Canadian banking division that have potentially put thousands of customers at risk.

According to that insider, whose identity wasn't revealed, customers' bank account information and other personal details – millions of names, addresses, account details, social insurance and credit card numbers, birth dates and transactions among other things – could be widely seen in a database with few privacy protections in place – accessed by more than 100 employees and shared with an unknown number of others.