An endoscope cleaning sheath includes a sheath main body, a distal-side fixing portion fixed to a distal portion of the sheath main body, and a proximal-side fixing portion fixed to a proximal portion of the sheath main body. The endoscope cleaning sheath includes a linear portion having a distal end fixed to the distal-side fixing portion at a distal-side connecting position and a proximal end fixed to the proximal-side fixing portion at a proximal-side connecting position, extended along a linear core axis between the distal-side connecting position and the proximal-side connecting position, and having a higher tensile strength in directions parallel to the longitudinal axis than the sheath main body.