Guns are seen throughout Heavy Rain. They can be used as evidence, a method of intimidation, and a tool for killing.
- The most featured gun seen is the Beretta 90-Two, which is wielded by Scott Shelby as well as most police officers (in "The Bear," "Fugitive," "On the Loose," and "The Old Warehouse").
- Norman Jayden uses a Beretta 92FS Inox.
- Carter Blake uses a SIG Sauer P226.
- Nathaniel Williams and Paco Mendez both wield a Colt M1911A1.
- Brad Silver uses a Remington 870 MCS shotgun to try and kill Ethan Mars.
- Jackson Neville and Andrew wield a Desert Eagle Mark XIX.
- Madison Paige and Charles Kramer both wield a Beretta 3032 Tomcat.
- A SIG Sauer P220 is used by the Origami Killer to kill Paco Mendez.
- Ethan can shoot Scott in the final battle in order to save Madison.
- Hassan can be shot in his shop if the player chooses to not interfere.
- When Scott breaks into Charles Kramer's mansion, the player can shoot all of his guards.
- Playing as Norman Jayden, you have the option to shoot Nathaniel Williams and kill him.
- Playing as Ethan Mars in the second to last trial, your mission is to find and shoot a man.
- Ethan can be shot by Carter Blake in "The Old Warehouse," as he is mistakenly thought to be pulling out a gun.
- In two of Ethan's epilogues in which Shaun dies ("Origami Blues" and "Tears in the Rain"), Ethan commits suicide by shooting himself. Many people believe that the gun is the gun from "The Shark."
- Lauren Winter uses a handgun (make unknown) to shoot the Origami Killer in "A Mother's Revenge."