Out of the Past is considered one of the greatest of all films noir. Robert Ottoson hailed the film as "the ne plus ultra of forties film noir".
Film critic Bosley Crowther wrote, "However, as we say, it's very snappy and quite intriguingly played by a cast that has been well and smartly directed by Jacques Tourneur. Robert Mitchum is magnificently cheeky and self-assured as the tangled 'private eye,' consuming an astronomical number of cigarettes in displaying his nonchalance. And Jane Greer is very sleek as his Delilah, Kirk Douglas is crisp as a big crook and Richard Webb, Virginia Huston, Rhonda Fleming and Dickie Moore are picturesque in other roles. If only we had some way of knowing what's going on in the last half of this film, we might get more pleasure from it. As it is, the challenge is worth a try."
The staff at Variety wrote, "Out of the Past is a hardboiled melodrama strong on characterization. Direction by Jacques Tourneur pays close attention to mood development, achieving realistic flavor that is further emphasized by real life settings and topnotch lensing by Nicholas Musuraca...Mitchum gives a very strong account of himself. Jane Greer as the baby-faced, charming killer is another lending potent interest. Kirk Douglas, the gangster, is believable and Paul Valentine makes role of henchman stand out. Rhonda Fleming is in briefly but effectively."
In a 2004 review of the film, critic Roger Ebert wrote "Out of the Past is one of the greatest of all film noirs, the story of a man who tries to break with his past and his weakness and start over again in a town, with a new job and a new girl. The film stars Robert Mitchum, whose weary eyes and laconic voice, whose very presence as a violent man wrapped in indifference, made him an archetypal noir actor. The story opens before we've even seen him, as trouble comes to town looking for him. A man from his past has seen him pumping gas, and now his old life reaches out and pulls him back." Ebert...