When Al Simmons (Michael Jai White) is still a (human) A-6 operative and has not yet become Spawn, he is seen on several missions carrying a Heckler & Koch MP5K as his weapon of choice. In the scene where he carries out an assassination at a military air base in Hong Kong, his MP5K is fitted with a suppressor.
Jessica Priest (Melinda Clarke) uses a Colt RO635 9mm SMG in the North Korean bio-chemical weapons plant; it is fitted with a flammable liquid-squirting canister under the barrel, a C-More red-dot sight, and a pair of laser sights.
Spawn (Michael Jai White) and various A-6 personnel are seen wielding weapons that appear to be FN P90 personal defense weapons. However, these "Faux P90"s are actually Cobray M11/9 machine pistols that have been visually modified to resemble P90s. In some scenes, the long stick-like magazines of the Cobrays can be seen protruding from beneath the weapons' grips as they are fired.
Spawn (Michael Jai White), Jessica Priest (Melinda Clarke), Jason Wynn (Martin Sheen), and many of the A-6 personnel are also seen using unusual silver machine pistols in many scenes. Like the movie's fake FN P90s, these are also Cobray M11/9s that have been dressed up with movie props to appear "futuristic".
While he is at A-6 talking to Jason Wynn, Al Simmons has a nickel-plated or stainless pistol in a shoulder holster. It appears to be a Beretta 92FS Inox, but this is not certain.
When Spawn fights the Violator (John Leguizamo), he uses an Olympic Arms OA-93 converted to full-auto and fitted with a buffer tube (a necessary modification for the weapon to fire full-auto as the longer full-auto bolt needs room to trip the auto sear). This same prop weapon also appears in a number of other movies, including Bad Boys and Clear and Present Danger.
In the A-6 armory, Spawn can be seen loading a magazine into a Heckler & Koch HK93 (it has the non-detachable lower receiver, plus the magazine well clearly reads "HK93").
At the hotel where Spawn crashes the Consortium party, a number of U.S. honor guard soldiers armed with M1917 Enfields join the A-6 personnel in shooting at Spawn while he was climbing up the outside of the hotel. The rifle stocks appeared to be painted white (or the rifles appear to be fitted with white fiberglass stocks) and are still able to cycle and fire live ammunition. Real parade rifles used by honor guards are typically deactivated, for the express purpose of preventing this exact situation from occurring.
When Spawn is planning to run off and kill the Clown, he grabs a short-barreled Steyr AUG from his arsenal which is only barely seen for a second. Due to a continuity error, the weapon becomes a Mossberg 500 Bullpup as soon as he turns around to face Cogliostro, who tells him that guns are useless. When Spawn is grabbing weapons from the A-6 armory, magazines for the AUG can be seen amongst the weaponry he has scattered across the floor, but the weapon itself can only be seen for a second later.
During the scene in which he breaks into the A-6 armory, Spawn can be seen loading up a short-barreled, stockless version of the Armsel Striker or its American cousin, the Street Sweeper. This weapon is fitted with an ADCO Square Shooter red-dot reflex sight, and it is portrayed in the film as a grenade launcher when it is used by the Clown (John Leguizamo).
