Proposed are a jet nozzle, and a combustor and a gas turbine including the jet nozzle. The jet nozzle is formed on an inner surface of a combustor to supply fluid into an interior of a liner of the combustor in a direction intersecting with a progress direction of combustion gases primarily combusted in a combustion chamber in the interior of the liner. The jet nozzle includes a fluid inlet, through which fluid is externally introduced, and a fluid outlet including a first fluid outlet member, through which a portion of the fluid introduced through the fluid inlet is discharged so as to be rotated in one direction, and a second fluid outlet member, through which the rest of the fluid is discharged so as to be rotated in a direction different from the rotation direction of the fluid discharged from the first fluid outlet member.