An endoscope cleaning sheath includes a tube body and a distal end configuration portion. The tube body includes an endoscope disposition hole in which an insertion portion of an endoscope provided with at least an observation window is inserted and disposed, at least one liquid supply hole configuring a liquid supply channel, and at least one gas supply hole configuring a gas supply channel. The distal end configuration portion is fixed to a distal end portion of the tube body. On an inner surface of a distal end surface portion of the distal end configuration portion is provided a fluid mixing portion and a concave portion configuring an ejection opening that ejects a fluid mixture at an observation window of the endoscope. The fluid mixing portion causes liquid supplied through the liquid supply hole and gas supplied through the gas supply hole to merge to mix the liquid and gas.