An endoscope insertion portion includes an imaging unit including a distal end optical member arranged at a distal end portion of the imaging unit and a movable optical member configured to be moved relative to the distal end optical member, an actuator unit arranged in a position relative to the distal end optical member, configured to drive the movable optical member and including a shape memory member configured to deform according to temperature, and a heater unit including a heating member configured to heat the distal end optical member wherein the heater unit is arranged on one side opposite to other side on which the actuator unit is arranged and the heating member is configured to heat the distal end optical member from the one side to the other side, relative to the optical axis of the imaging unit, when viewing in the axial direction of the insertion portion.
