MetLife, Inc. is the holding corporation for the Metropolitan Life Insurance Company (MLIC),[2] better known as MetLife, and its affiliates. MetLife is among the largest global providers of insurance, annuities, and employee benefit programs, with 90 million customers in over 60 countries. The firm was founded on March 24, 1868. MetLife ranked No. 43 in the 2018 Fortune 500 list of the largest United States corporations by total revenue.

On January 6, 1915, MetLife completed the mutualization process, changing from a stock life insurance company owned by individuals to a mutual company operating without external shareholders and for the benefit of policyholders. After 85 years as a mutual company, MetLife demutualized into a publicly traded company with an initial public offering in 2000.[8] Through its subsidiaries and affiliates, MetLife holds leading market positions in the United States, Japan, Latin America, Asia's Pacific region, Europe, and the Middle East. MetLife serves 90 of the largest Fortune 500 companies.

The company's head offices and boardroom are located at the MetLife Building at 200 Park Avenue in Midtown Manhattan, New York City, which MetLife owned from 1981 to 2005; despite the sale, MetLife increased its leased footprint in the building beginning in 2015.