An individual, commercial entity, government body or other party with a real interest, or stake, in a given activity or occurrence. Both a stockholder in a utility and a customer of that utility can be considered stakeholders in that utility's activities, because they can both be affected by the utility's actions and policies.

The term is generally used to refer to a party with a financial interest, specifically ownership or part-ownership of the thing referred to, but a non-financial interest can also be thought of as a stake.