Cara Delevingne uses an American accent to play Dr. June Moone, but in order to play her dark side (the Enchantress), she uses her natural British accent.
David Ayer heavily considered casting Freddy Rodriguez as Chato Santana/El Diablo before finalizing on Jay Hernandez.
When Diablo demonstrates his powers to Captain Boomerang, a demonic, skeletal face with glowing eyes flashes within the flames. It is the same creature Diablo turns into later in the film. It is the personification of the fire-demon 'spirit of vengeance' that inhabits Diablo.
Director David Ayer makes a cameo in the Extended Cut of the film as a Belle Reve Penitentiary guard.
Harley Quinn's revolver is a .357 Magnum customized Chiappa "Rhino" 60DS with white grips inlaid with a gold Joker emblem and gold decoration on the barrel shroud.
The blue-black camouflage pattern used by the U.S. Navy SEALs in the film is a combination of several patterns, including the Desert Storm-era 'chocolate chip' desert pattern, the new U.S. Army standard Multicam/Operational Camouflage Pattern, a US Marine 'Urban-T' pattern from 1999, 'Flecktarn', and the French 'Lizard' pattern, known overall as 'Bravoflauge'.
David Ayer cast Cara Delevingne before there was an actual script. He asked her to prepare for her role as Enchantress by stripping naked in the woods, preferably underneath a full moon, and walking in the mud at night. She reportedly did so, on the secluded compound of her sister's mansion, for some much-needed privacy.
The Flash's (Ezra Miller) only line in the movie "No honor among thieves, eh?" is a reference to the 1990 series The Flash episode titled "Honor Among Thieves".
Ted Whittall (Admiral Olsen) portrayed Rick Flag in the Suicide Squad version of Smallville (2001).
When the Team's chopper is hit and is going down the pilot states "Six-one is going down." In the movie "Black Hawk Down" the first helicopter hit by an RPG is called "Super six-one."
The dead pig that Jared Leto sent the cast is actually seen when they're doing the feeding sessions to the inmates as they a drop the dead pig into Killer Croc's cell. It was later confirmed that this was the actual pig that was sent that was used in the film.
This is the second movie Will Smith and Margot Robbie starred. They took the main roles in the film Focus.
Only modern DC film to feature Batman not to be produced by Michael Uslan
Part of this film is set in Midway City. In the DC Comics, this was the home of the superhero couple Hawkman and Hawkgirl.
The Enchantress is the name of villainous characters in both DC and Marvel Comics, who coincidentally both wield magic and are clothed in green. The Enchantress of Marvel is a rival of Thor, while DC's is not primarily an antagonist on any one hero. In this film, she has been completely re-designed in order to look visually different and unique.
Jai Courtney was rumored to be in talks for Deadshot before being cast for Captain Boomerang.
When perfecting the Joker's laugh, Jared Leto publicly tried different laughs in New York City and Toronto to see which ones made people the most uncomfortable.
Will Smith and spouse Jada Pinkett Smith, both have acted as a character from Gotham City.
The helicopter crash scene was the last to be shot just in case any of the actors got injured and filming was delayed.
The military helicopters in the film are either MH-60L Direct Action Penetrator (DAP) Black Hawk gunships or MH-47G Chinooks. Both are flown exclusively by the elite 160th Special Operations Aviation Regiment (SOAR) for special missions, like supporting the Suicide Squad in the film.
In killer croc's cell at the end of the film, the music video is he watching is Tech n9ne "dwamn".
David Ayer considered giving Shia LeBouf a part in the film, however Warner Bros allegedly vetoed this decision, due to his reputation.
David Ayer was thought about giving Shia LeBouf a play but Warner Bros refuse because Shia had a bad reputation.