The prefabricated universal structural steel panel and panel system includes a generally elongated rectangular panel having an opposed exterior and interior surfaces, an opposed first and second end portions, and an opposed first and second side edge portions. At least two stiffening ribs are integrally formed in the panel and extend longitudinally between the first and second end portions. The first side edge portion has a beveled configuration and is integrally connected to an elongated male connecting member. An elongated female connecting member is integrally connected to the second side edge portion and extends adjacent the interior surface to define a fold. The elongated male connecting member of one panel is cooperatively profiled to mate with the female connecting member of an adjacent panel.