Tom McCarthy explained in an interview how he and Matt Damon immersed themselves in the culture of Oklahoma oil "roughnecks" for the film: "Matt and I started going to Oklahoma early on to get a taste of the place and the people and spending time with roughnecks, in particular. They really opened up their lives to us, and their worlds and their families. They were incredibly instrumental in helping us shape the story."
Abigail Breslin obtained her driver's license two weeks before shooting began, as one scene required her to drive a car.
Matt Damon and his team received a 5-minute standing ovation at the 74th Cannes Film festival where the film premiered in July 2021.
Loosely based on the Amanda Knox story, although shortly before the film's release she expressed anger, claiming the movie is profiting off her life and struggle. She posted on Twitter, "Does my name belong to me? My face? What about my life? My story? Why does my name refer to events I had no hand in? I return to these questions because others continue to profit off my name, face, and story without my consent. Most recently, the film Stillwater."
The address of Matt Damon's character's home, 2823 S Walking Trail Drive, 74074 Stillwater OK, really exists. However, it is a vacant lot.