Ted Mills’s review published on Letterboxd :
Martin McDonagh should definitely get a Oscar nod at least for this script, which out of the three features he's directed so far, is by far his most mature and emotionally resonant, similar to the best of his plays. Scenes that can turn from hilarious to poignant and wrenching are bloody hard to do, but Three Billboards has many of them. Frances McDormand is a treasure (this and Olive Kitteridge are some of her best work) and her angry and distraught mother goes through all levels of rage and grief, yet with a prickly humor that saves the film. In fact all the characters surprise along the way, from Woody Harrelson's chief to Peter Dinklage's minor supporting character, but the biggest surprise is Sam Rockwell who literally comes out of a crucible a different man. It took an Irishman to deliver a diagnosis of a changing America, and I'm glad it's McDonagh. The ending is perfect, a question to all of us.