StormofCuteness’s review published on Letterboxd:
Finally! I noticed in a lot of reviews people congratulating Hitchcock for the exquisite plotting in this, but those accolades belong to Frederick Knott who wrote the stageplay (successful on both the West End and Broadway) as well as the screenplay. Hitchcock's best decisions were in casting two vets from the play (Inspector/Williams and Swann/Dawson) and of course, Grace Kelly. That said, it takes a director of his ability to make a basic one set play suspenseful and intriguing enough to keep the audience entertained. I was very entertained and truly enjoyed the film (especially Williams). Not a masterpiece, but definitely well-worth seeing.