Aflac Incorporated /ˈæflæk/ is the largest provider of supplemental insurance in the United States, founded in 1955 and based in Columbus, Georgia. In the United States, Aflac underwrites a wide range of insurance policies, but is perhaps more known for its payroll deduction insurance coverage, which pays cash benefits when a policyholder has a covered accident or illness. The company states it insures "one of four Japanese households" and is "the largest life insurer in Japan in terms of individual insurance policies in force". Aflac 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. However, its market share is higher than its next four competitors combined.

Aflac has a field force of over 72,500 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, Paul and Bill Amos, in 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.