A linear electro-mechanical actuator includes a containment structure (2), a nut (5) positioned in the containment structure (2), a screw shaft (6) inserted in the nut (5) and interconnected with the nut (5) via a helical recirculating ball coupling, and an anti-rotation mechanism (9) positioned inside the screw shaft (6) to prevent the screw shaft (6) from rotating about the axis (X). The anti-rotation mechanism (9) includes a guide unit (10) fixed cantilever-style to the containment structure (2) and connected to the screw shaft by a non-rotational coupling.