The invention refers to a suspension pylon (4) for an aircraft engine (2), the pylon including a rigid structure (10) forming a box provided with a lower spar (28) and an upper spar (26), and an engine mounting system (11) installed fixed on the structure (10) and in particular including a forward attachment (6) with an attachment body provided with a horizontal fixing surface (40) held in contact with a horizontal fixing surface (38) of the structure (10). According to the invention, the attachment body is arranged such that its horizontal fixing surface (40) is located along a vertical direction (Z) of the pylon, upwards from a forward end (28a) of the lower spar and downwards from a forward end (26a) of the upper spar. Furthermore, the structure (10) includes at least one forward fitting (42a, 42b) making up a forward closing rib (36) of the box, this fitting (42a, 42b) defining said horizontal fixing surface (38).