An articulated joint for connection between a liquid supply line and a barrel (P) of a sprinkler (J), comprising a fixed tubular body (2) adapted to be connected to the supply line (A); a movable tubular body (3) adapted to be coupled to the fixed tubular body (2) and to be connected to the barrel (P); wherein each body (2, 3) has at least one curved end portion (1 1, 12) having the same curvature, wherein one of these curved ends slidingly fits into the other curved end portion with sealing means (13) interposed therebetween; and wherein, once said tubular bodies (2, 3) have been coupled, they define a common plane of curvature (ττ) and are hinged to each other about a transverse axis (T) that is substantially perpendicular to said plane of curvature (ττ) to allow relative inclination thereof; means (24) are also provided for adjusting the relative inclination angle (a), which comprise at least one plate-like member (25) substantially parallel to the plane (ττ) and laterally secured to one of the bodies (2, 3), the plate-like member (25) being formed with a plurality of through holes (30) for receiving a first pin (31 ) that can be fitted into at least one seat (32) formed on the other body (2, 3) for selectively locking said relative inclination angle (a).