Aflac Incorporated is the largest provider of supplemental insurance in the United States, founded in 1955 and based in MidTown Columbus, Georgia. In the United States, Aflac underwrites a wide range of insurance policies, but is perhaps best known for its payroll deduction insurance coverage, which pay cash benefits when a policyholder has a covered accident or illness. In Japan, the company is the second largest insurer overall and the largest life insurer, and is also well known for its supplemental medical policies. Aflac currently is the number one Supplemental Health provider in the U.S. followed closely by Allstate Workplace Division. Aflac employs many people in Columbus and its other locations. Aflac has one of the largest field forces with over 7,500 agents in the U.S. In 2009 Aflac acquired Continental American Insurance Company to expand its coverage beyond voluntary benefits alone.

The company was founded by three brothers, John Amos, Paul Amos, and Bill Amos, in Midtown Columbus, Georgia, in 1955 as American Family Life Insurance Company of Columbus. In 1964, the company name was changed to American Family Life Assurance Company of Columbus. The company, in 1990, adopted the Aflac initialism, although the official name of the underwriting subsidiary remains American Family Life Assurance Company of Columbus.

The company signed 6,426 policyholders in its first year. Aflac pioneered cancer insurance in 1958. Beginning in 1964, the company decided to focus sales on worksite settings, eventually through policies sponsored by employers and funded through payroll deductions. By 2003, more than 98% of Aflac policies in the United States were issued on a payroll deduction basis, making the company a leader in that approach to policy distribution. In 1973, Aflac established a holding company, the American Family Corporation.

Aflac operates in the United States and Japan, and has its worldwide headquarters and corporate offices in an eighteen story tower just east of Downtown Columbus, Georgia and is the tallest building in the city. At the end of 2009, the corporation's total assets were more than $84 billion, and the company insured more than 60 million people worldwide. Aflac is the largest provider of guaranteed-renewable insurance in the United States and the largest insurance company overall in Japan, when measured by individual insurance policies in force. Aflac launched a campaign in 2001 to promote their first accident policy in Japan, which The Wall Street Journal rated as one of the "ten most effective campaigns of 2000."