Former California Governor Leland Stanford founded Pacific Mutual Life in Sacramento, California in 1868. Stanford served as Pacific Life's first president, and also founded Stanford University as a tribute and memorial to his son. Furthermore, when Mr. Stanford died and the university was unable to pay its professors salaries Mrs. Stanford used his life insurance policy to pay them and ensure that the school stayed open.

By 1885 accident insurance was also available through Pacific Life, as a response to the growing needs of their policyholders. Pacific Mutual Life and Conservative Life, a life insurance company from Los Angeles, merged just days before the earthquake and fires of San Francisco in 1906 destroyed the Pacific Life home office. Consequently, on May 18th, 1906 the Board of Directors met and decided to change their home office location to Los Angeles.

Pacific Life's innovative non-cancellable disability policies were wildly popular but proved to be a tremendous drain on the company as the Great Depression caused unemployment rates to soar, seriously threatening the company's future. In 1955 Pacific Life became one of the first companies to utilize computer technology to assist with day to day operation and data storage, and the first company west of the Mississippi River to operate a Univac I large scale data processing unit.

By the late 1970s Pacific Life had invested heavily in technology and believed that a high-tech corporate office environment would be beneficial to employees and profits. In 1972 Pacific Life moved its home office to a brand new, modernized building in Newport Beach, California. Throughout the 1980s Pacific Life steadily increased its capital and revenue and was able to expand significantly, and in the mid 1990s they merged the former First Capital Life insurance company into Pacific Mutual Life.

In 1997 Pacific Mutual Life became a publicly traded company and modified its name to reflect that, renaming itself Pacific Life Insurance Company since the company converted from a mutual company to a publicly traded company.