An optical fiber cutter includes: a base member; a movable member that clamps the optical fiber extending from a fiber holder and that moves with respect to the base member between an advanced position and a retracted position in an extending direction of the optical fiber; a biasing member that biases the movable member at the retracted position forward; a locking member that regulates forward movement of the movable member at the retracted position; a cutter supporter that supports a blade that forms an initial cut in the optical fiber, that moves in a direction that intersects with the extending direction of the optical fiber, and that forms the initial cut at an initial cut forming position between the fiber holder and the movable member; and an unlocking member that releases the regulation of forward movement of the movable member before the blade reaches the initial cut forming position.