Joel Edgerton admitted in multiple interviews that despite the extensive makeup, whenever they filmed outside in public he was largely ignored by spectators due to the presence of Will Smith.
Max Landis stated that he turned down an additional $1 million for the sale of the script because he wanted David Ayer to direct. He had written the script specifically for Ayer.
The tattoo on Poison's forehead says "Only God can judge me" in Spanish.