Development
While traveling through the Southern United States c. 1998, Martin McDonagh came across a couple of accusatory billboards that alleged a woman named Kathy Page had been murdered by her husband Steve Page in Vidor, Texas, and highlighted the incompetence of the police in solving the case. McDonagh described the billboards, which he presumed had been put up by the victim's mother, as "raging and painful and tragic" and was deeply affected by them, saying the image "stayed in my mind [...] kept gnawing at me".[7][a] This incident, combined with his desire to create strong female characters, inspired McDonagh to write the story for Three Billboards Outside Ebbing, Missouri.[7] He said it took him about ten years to decide "it was a mother who had taken these things out. It all became fiction [...] based on a couple of actual billboards".[9][10]
Casting
The character of Mildred was written with Frances McDormand in mind, and the character of Dixon was written specially for Sam Rockwell.[11] McDormand initially felt she was older than the character as it was written and suggested Mildred be Angela's grandmother, rather than her mother, but McDonagh disagreed, feeling it would change the story too much,[11][12] and eventually McDormand's husband Joel Coen persuaded her to take the part regardless.[11]
John Wayne served as an inspiration for McDormand in her portrayal of Mildred, and Rockwell, wanting to make his character "the exact opposite" of Mildred, took inspiration from Lee Marvin, Wayne's co-star in The Man Who Shot Liberty Valance.[11]
Filming
Principal photography began on May 2, 2016, in Sylva, North Carolina,[13] and ran for 33 days.[14] Allison Outdoor Advertising of Sylva built the billboards, which were put in a pasture near Black Mountain, North Carolina, 60 miles east of Sylva. When not filming, the billboards were usually covered because people in the area found them upsetting. David Penix of Arden, North Carolina, subsequently bought the billboards and used the wood for a roof in Douglas Lake, Tennessee, though the messages are no longer legible.[15]
Town Pump Tavern in Black Mountain, which had been featured in The World Made Straight (2015), was closed for three days while filming took place inside. A pool table and booths were added, but the bar's actual sign appears in the film.[16]
