A vessel propulsion apparatus includes a second shaft that is inserted in a first driven gear and in a second driven gear, that is connected to a dog clutch, and that is arranged to undergo a thrust. The vessel propulsion apparatus includes a first bearing disposed between the first driven gear and the second shaft, a second bearing disposed between the second driven gear and the second shaft, and a case to which a thrust applied to the second shaft is transmitted via the first bearing and the first driven gear or via the second bearing and the second driven gear. The vessel propulsion apparatus includes an adjusting member disposed between the second shaft and at least one of the first driven gear and the second driven gear and arranged to apply a preload onto the first bearing and the second bearing.