An ultrasound endoscope includes: a plurality of piezoelectric elements that are arranged to form a cylinder such that respective longitudinal directions of the piezoelectric elements are aligned, each piezoelectric element being configured to transmit and receive an ultrasound wave; an acoustic lens that is located on outer peripheries of the piezoelectric elements, the acoustic lens being configured to converge ultrasound waves generated by the piezoelectric elements on an outside of the acoustic lens, and transmit ultrasound waves input from the outside of the acoustic lens to the piezoelectric elements; a housing configured to hold distal end sides and proximal end sides of both of the piezoelectric elements and the acoustic lens; and a flexible material that is located between either a distal end or a proximal end of the acoustic lens and the housing, and that has a lower elastic modulus than the acoustic lens.