I Am Legend is the 2007 science fiction action film directed by Francis Lawrence and stars Will Smith as a US Army doctor who struggles to find a cure to the virus that has affected nearly the entire population of the world. The film is the third official film adaptation of Richard Matheson's sci-fi novel of the same name, the first being 1964's The Last Man on Earth and the second being 1971's The Omega Man starring Charlton Heston.
The following weapons were used in the film I Am Legend:
Dr. Robert Neville (Will Smith) uses a Heckler & Koch Mark 23 with a flat earth (tan) frame as his main sidearm. He is seen with it holstered, but also carries one in the driver's door, most notably to shooting the infected dogs in the middle of the film. There were several identical firing Mark 23s used on-set, as well as rubber versions for stunt work. For most scenes where Will Smith carried the weapon in the holster, a lightweight airsoft Mark 23 (with frame painted tan to match the firing pistols) was used.
Beretta 92FS
Neville (Will Smith) keeps a Beretta 92FS on his nightstand. In the alternate ending to the film, Anna picks up the Beretta.
Smith & Wesson 5946
Robert Neville (Will Smith) draws a Smith & Wesson 5946 on Anna (Alice Braga) and Ethan (Charlie Tahan). The 5946 in the DAO setting is one of three pistols used by the NYPD (the other two being the Glock 19 and the P226 DAO), so it was likely recovered by Neville from an NYPD precinct.
Special Weapons SP-10s are used by the two Army Rangers that escort Dr. Neville to the dock. The first seen when Neville says, "Five minutes, we'll make it". The second when Dr. Neville orders the other troops to "get your hands off my wife".
Rifles & Carbines
Colt Law Enforcement Model 6920 Carbine
Robert Neville (Will Smith) uses a semi-automatic Colt AR-15 model that closely resembles an M4A1 carbine; this variant is referred to in the company's catalog as the "Law Enforcement Carbine", or the Model 6920 (see here for more info on this model). The LE Carbine is a semi-automatic-only variant of the M4 with a 16" barrel, but according to the Propstore of London, the weapon was modified to fire automatic for the film. His AR is also equipped with an ACOG (TA31 Series) sight attachment throughout the movie. The tactical light on the gun is a Pentagon MD3R.
M16A2
One of the guards is armed with an M16A2 at the safe haven. Several US soldiers armed with M16 rifles at the checkpoint seen in a flashback.
M4A1
The M4A1 is used by US Army Personnel at the harbor during the evacuation scene. One of the M4A1s clearly has a C-More reflex sight on top and a regular handguard. Others have regular iron sights. (at the part where Dr. Neville says, "Scan her again!")
DPMS Panther LRT SASS
When Neville (Will Smith) opens up his closet arsenal, a long rifle can be seen on the right next next to his M249 SAW. This rifle appears to be a DPMS Panther LRT SASS rifle.
Machine Gun
M249-E2 SAW
When Dr. Neville (Will Smith) opens his arms cabinet, an M249-E2 can be seen, along with another M4A1 Carbine with the flashlight on the opposite side.
The weapon light used in the movie is a PentagonLight™ MD3R, most notably when he searches for Sam in a dark, abandoned bank.
Trijicon ACOG (Advanced Combat Optical Gunsight) TA31 Model
The optic Neville used on his AR is a Trijicon ACOG TA31F. However, the movie displayed an incorrect reticle for the optic, instead using the reticle of a PSO-1 scope as used on the Russian SVD Dragunov.
Knights Armament RAS
Neville had numerous ARs in various configurations in his arsenal. One of his ARs was equipped with a Knights Armament Company RAS.
ERGO Rail Covers
Neville had Ergo rail covers (11) on one of his ARs in the film.