A buy–sell agreement, also known as a buyout agreement, is a legally binding agreement between co-owners of a business that governs the situation if a co-owner dies or is otherwise forced to leave the business, or chooses to leave the business.

It may be thought of as a sort of premarital agreement between business partners/shareholders or is sometimes called a "business will". An insured buy–sell agreement (triggered buyout is funded with life insurance on the participating owners' lives) is often recommended by business-succession specialists and financial planners to ensure that the buy–sell arrangement is well-funded and to guarantee that there will be money when the buy–sell event is triggered.