A rotor for a rotary electric machine; the rotor comprising: a shaft, which is mounted so as to rotate around a rotation axis; a magnetic core, which is arranged around the shaft and consists of a plurality of lamination sheets stacked together; a series of axial slots, which are obtained inside the magnetic core; a series of permanent magnets, which are arranged in the slots of the magnetic core; and a pair of end discs, which are arranged around the shaft at the two opposite ends of the magnetic core and are designed to keep the lamination sheets of the magnetic core stacked together; wherein the end discs have balancing holes, which are arranged asymmetrically relative to the rotation axis and dynamically balance the rotor around the rotation axis; and wherein each end disc consists of an inner component with an annular shape, which is arranged around the shaft in a radial position more on the inside than the permanent magnets and is made of a first metal material, and of an outer component with an annular shape, which is arranged around the inner component, faces the permanent magnets, and is made of a second metal material, which is different from the first metal material and is non-magnetic; the rotor is characterized in that: the outer component of each end disc is provided with the balancing holes; and in each end disc, the inner component has a series of recesses, which originate from an outer edge of the inner component, are "U"-shaped, and are arranged in the area of the slots of the magnetic core so as to be arranged in the area of the permanent magnets. a shaft, which is mounted so as to rotate around a rotation axis; a magnetic core, which is arranged around the shaft and consists of a plurality of lamination sheets stacked together; a series of axial slots, which are obtained inside the magnetic core; a series of permanent magnets, which are arranged in the slots of the magnetic core; and a pair of end discs, which are arranged around the shaft at the two opposite ends of the magnetic core and are designed to keep the lamination sheets of the magnetic core stacked together; wherein the end discs have balancing holes, which are arranged asymmetrically relative to the rotation axis and dynamically balance the rotor around the rotation axis; and wherein each end disc consists of an inner component with an annular shape, which is arranged around the shaft in a radial position more on the inside than the permanent magnets and is made of a first metal material, and of an outer component with an annular shape, which is arranged around the inner component, faces the permanent magnets, and is made of a second metal material, which is different from the first metal material and is non-magnetic; the rotor is characterized in that: the outer component of each end disc is provided with the balancing holes; and in each end disc, the inner component has a series of recesses, which originate from an outer edge of the inner component, are "U"-shaped, and are arranged in the area of the slots of the magnetic core so as to be arranged in the area of the permanent magnets. the outer component of each end disc is provided with the balancing holes; and in each end disc, the inner component has a series of recesses, which originate from an outer edge of the inner component, are "U"-shaped, and are arranged in the area of the slots of the magnetic core so as to be arranged in the area of the permanent magnets.