A marine vessel maneuvering supporting apparatus is used in a marine vessel which includes a propulsion system and a steering mechanism. The marine vessel maneuvering supporting apparatus includes a first operational unit arranged select a forward drive position for forward drive of the propulsion system, a reverse drive position for reverse drive of the propulsion system, and a neutral position for an inactive state of the propulsion system, a second operational unit arranged to command rightward and leftward movement of the marine vessel, and a target value computing unit arranged to determine target values including a target propulsive force for the propulsion system and a target steering angle for the steering mechanism, such that the marine vessel undergoes parallel movement in a direction that is in accordance with an operation position of the first operational unit when rightward or leftward movement is commanded by the second operational unit.