An articulated connection joint between a liquid supply line and a sprinkler barrel includes a fixed tubular body to be connected to the supply line and a movable tubular body to be connected to the fixed tubular body and to the barrel. These bodies have end portions with equal curvature, one of which slidingly fits into the other one with a sealing element interposed therebetween. The tubular bodies, once coupled, define a common curvature plane and are hinged to each other about a transverse axis, which is substantially perpendicular to the curvature plane to provide for a relative inclination that can be adjusted with a plate-shaped member substantially parallel to the curvature plane and laterally secured to one of the bodies. A plurality of through holes in the plate-shaped member can receive a first pin fitted into a seat formed on the other body to selectively lock the inclination angle.