A hub bearing unit (1) comprising an outer ring (3); an inner ring (6) rotating about a common symmetry axis (A) of the outer ring and of the inner ring; a flange (4) which extends radially from the outer ring (3); a plurality of rolling bodies (7) interposed between the outer ring and the inner ring; a sealing assembly (8) and a protective shield (10) for the sealing assembly (8), arranged on the side opposite to the flange (4); wherein the protective shield (10) is constituted by a metal sheet and comprises a cylindrical portion (14) which can be mounted integral with a stationary axle (2), and a flange portion (15), which extends radially on the outside of the cylindrical portion (14), facing the sealing assembly (8), from a first end (16) of the cylindrical portion (14) opposite to the flange (4) of the outer ring (3); a second end (23) of the cylindrical portion (14) is provided radially inwards with an L-fold (24) which delimits an annular axial shoulder (26) cooperating in abutment with the inner ring (6).
