Abstract: To provide a nanobubble generating nozzle that is compact and capable of generating nanobubbles with high efficiency. The problem is solved by a nanobubble generating nozzle and a nanobubble generator including this nanobubble generating nozzle. The nanobubble generating nozzle includes an introduction part for introducing a mixed fluid of a liquid and a gas into an interior thereof, a jetting part for feeding out the mixed fluid containing nanobubbles of the gas, and a nanobubble generating structure part for generating nanobubbles of the gas, between the introduction part and the jetting part. The nanobubble generating structure part includes a plurality of flow paths having different cross-sectional areas through which the mixed fluid of the liquid and the gas is passed, in an axial direction of the nanobubble generating nozzle.