An information processing system (3000) includes a marker (3020). The marker (3020) is any part of the body of a user of the information processing system (3000), or is any object attached to the user of the information processing system (3000). An information processing apparatus (2000) includes an operation region extraction unit (2020) and a recognition unit (2040). The operation region extraction unit (2020) extracts an operation region from a captured image on the basis of a position of the marker (3020). The recognition unit (2040) calculates a position or motion of an operation body in the operation region on a captured image. The recognition unit (2040) recognizes an input operation on the basis of the calculated position or motion of the operation body.