A ship propulsion device controller controls a plurality of ship propulsion devices disposed on a rear portion of a hull of a ship. The ship includes an operation unit configured to operate the ship propulsion devices. The operation unit is able to be positioned at a first position where the ship propulsion devices do not generate propulsion forces for the ship and a second position where the ship propulsion devices generate propulsion forces for moving the ship in a right direction, a right-forward direction, or a right-backward direction or a third position where the ship propulsion devices generate a propulsion force for moving the ship in a left direction, a left-forward direction, or a left-backward direction. When the operation unit is moved from the first position to the second position and maintained at the second position, the ship propulsion devices generate a clockwise rotating moment in the ship during a first period from a first timing when the operation unit is moved to the second position to a second timing and do not to generate the clockwise rotating moment in the ship during a second period after the second timing.