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.
- Ethan Mars uses a Taurus PT92 during one of his trials.
- Brad Silver uses a Remington 870 MCS shotgun.
- Jackson Neville and Andrew both wield a Desert Eagle Mark XIX.
- Madison Paige and Charles Kramer both wield a Beretta 3032 Tomcat.
- The Origami Killer uses a SIG Sauer P220 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 endings in which Shaun dies ("Origami Blues" and "Tears in the Rain"), Ethan commits suicide by shooting himself with a gun identical to the one he uses in "The Shark."
- Lauren Winter uses a handgun (make unknown) to shoot the Origami Killer in "A Mother's Revenge."