A rotary joint, particularly for fluid-driven transmission, comprising a main body, which can be arranged between a drive unit and a driven element, provided with the possibility to rotate, with respect to the drive unit, about a rotation axis (A). The main body is provided with a first stator half-joint (2), rigidly associable with the drive unit, and a second rotor half-joint (3), which is engaged with the first half-joint (2) so that it can rotate about the rotation axis (A) and can be coupled rigidly to the driven element. The first half-joint (2) and the second half-joint (3) are crossed by respective branches of a channel system (4) that can be crossed by a fluid and the branches are kept mutually facing at any mutual angular position of the half-joints (2, 3), for the fluid-driven connection between the drive unit and the driven element. The main body has an internal cavity (5), which is extended along the rotation axis (A). The cavity (5) accommodates an auxiliary body (6) which comprises at least one first electric stator connector (7), rigidly coupled to the first half-joint (2) and electrically connected to the drive unit, and at least one second rotor connector (8), which is electrically connected to the driven element. The second connector (8) is rigidly coupled to the second half-joint (3) and can rotate about the rotation axis (A). The connectors (7, 8) are kept mutually electrically associated at any mutual angular position of the half-joints (2, 3), for the electrical connection between the drive unit and the driven element.