A Colt Detective Special can be seen laying on the floor in a flashback of Dr. Richard Kimble's (Harrison Ford) when he is asked by an officer if he kept a gun in the house.
Remington 870
A prison guard on the bus are armed with Remington 870 shotguns. One of the guards using a Mossberg 500 has his gun switch to an 870 in some shots, as described below.
Mossberg 500
The old prison guard (Richard Riehle) uses a Mossberg 500 to shoot an inmate who shanks another guard with a sharpened toothbrush handle. It switches to a Remington 870 in some shots.
Glock 17
U.S. Marshal Samuel Gerard (Tommy Lee Jones) uses a Glock 17 2nd generation as his sidearm of choice. When in the sewer, he trips and drops his Glock and Kimble takes it. He draws a spare Glock 17 out of a vest compartment and uses it for the rest of the film. While in the sequel, U.S. Marshals, Gerard is said to use a Glock 22, this does not confirm the model in this film. At the time this film was made, most of the pistols in the hands of law enforcement officers in the U.S. (and most of those in Hollywood's rental armories) were 9x19mms. Close inspection of the bore shows they are likely Glock 17s anyway.
Glock 19
U.S. Marshall Deputy Cosmo Renfro's (Joe Pantoliano) sidearm is a Glock 19 the compact 9x19mm version of the Glock 17. He is seen using it in the seen when they are closing in on Kimble in the laundrey room. Renfro is knocked unconcious by Dr. Charles Nichols (Jeroen Krabbe) and has the Glock stolen from him.
SIG-Sauer P226
A nickel SIG-Sauer P226 is seen the hands of Deputy Marshal Noah Newman (Tom Wood) as his personal sidearm. The 2nd Fugitive, Copeland (Eddie Bo Smith Jr.) gets a hold of the weapon and holds Newman hostage with it until he is killed by Gerard. Deputy Marshal Robert Biggs (Daniel Roebuck) is seen entering the door with a black K-Kote model as well.
Smith & Wesson 5906
Deputy Marshal Poole (L. Scott Caldwell) keeps a Smith & Wesson 5906 as her sidearm of choice and is seen using it when apprehending the second fugitive.
Beretta 92FS
A deputy can be seen entering Copeland's hideout armed with a Beretta 92FS. In flashbacks to the murder, Sykes is seen holding a suppressed 92FS in Kimble's home, but is not seen using it.
Smith & Wesson Model 66
Frederick Sykes (Andreas Katsulas), tries to kill Kimble on an El-train armed with a Smith & Wesson Model 66 .357 stainless snub-nose revolver. They struggle and Kimble ends up dissarming him (ironically) of his weapon.
Llama Comanche
A member of the Chicago P.D. (Neil Flynn) uses a Llama Comanche revolver (noted by barrel ribbing and ejector shroud) with rubber grips to attempt to arrest Kimble before Sykes shoots him with his Smith & Wesson Model 66.
It might also be a Colt Trooper, which was made with a ventilated rib barrel and ejector shroud. BTW: I think that the pic does not show a .357 magnum Llama Comanche, but a .38 special Llama "Martial" (these were released with "service" style grips, while most Comanches had "Target" grips.
Colt Commando Variant
A Chicago P.D. sniper fires shots at Kimble on the roof with his Colt Commando rifle variant during the climax of the film.
Heckler & Koch HK91
A SWAT officer is briefly seen holding a Heckler & Koch HK91 rifle fitted with a snap on scope and 30 round magazine at the film's end.