Critical reception
My Week with Marilyn received generally positive reviews from critics, with Williams' performance receiving acclaim. Review aggregator Rotten Tomatoes reports that 82% of 187 critics have given the film a positive review, with a rating average of 7.10/10. According to the site's summary of the critical consensus, "Michelle Williams shines in My Week with Marilyn, capturing the magnetism and vulnerability of Marilyn Monroe." On Metacritic, the film holds a score of 65 out of 100, based on 38 reviews, indicating "generally favorable reviews". Audiences surveyed by CinemaScore gave the film an average grade of "A−" on an A+ to F scale.
David Rooney from The Hollywood Reporter praised Williams' performance and said she nailed Monroe's vocal style. Rooney also praised Redmayne as Clark, saying his scenes with Williams were captivating. However, Rooney went on to say "Fault lies with both Hodges' workmanlike script and Curtis' failure to excavate much psychological depth." He added My Week with Marilyn is starchy and short on perspective, making it "superficial showbiz pageantry." Ronnie Scheib of Variety said My Week with Marilyn "flits uneasily between arch drawing-room comedy and foreshadowed tragedy" and is too stagily directed by Curtis, who lines up the characters with "no attention to spatial logic or rhythmic flow." Scheib added the film coasts on Williams' performance, while the story feels like it has been ripped from film fan magazines of the time. Rex Reed of The New York Observer called My Week with Marilyn "pure perfection."
Adam Green of Vogue said the film does not quite reach "the high drama and urgency of a period piece like The King's Speech", but it does evoke a vanished era in filmmaking. Green added Williams is the main attraction and she brings Monroe to life "with heartbreaking delicacy and precision without resorting to impersonation or cliché." Regina Weinreich of The Huffington Post called My Week with Marilyn a "gem" and said the story "manages to convey so much of Marilyn, particularly her child-like vulnerability, her insecurity as an actress, her natural charm and talents. While we have seen Michelle Williams tap dance and heard her sing before -- she was superb in last year's Blue Valentine -- her moves and voice as Marilyn evoke the subject's understated, magnetic performances." Weinreich went on to praise the rest of the cast, including Redmayne, Branagh and Dench, saying they are "especially good." A writer for indieWire said My Week with Marilyn is like a "superficial Lifetime made for TV-movie." The writer went on to say the film is not terrible, but there is "very little meat on the bone." They added the film has a terrific cast who do their best with an average script. Robbie Collin, writing for The Daily Telegraph gave the film three out of five stars and said "Michelle Williams makes a mesmeric Monroe in My Week With Marilyn, but the film falls disappointingly short on boop-boop-be-doo."
The Miami Herald's Rene Rodriguez gave the film three out of four stars. He said "One of the chief pleasures of My Week with Marilyn — which should not be approached as anything other than fluffy entertainment — is watching Williams bring to life Monroe's inner demons and her movie-star allure with equal aplomb." The New Yorker's film critic David Denby also praised Williams' performance as Monroe, saying "In My Week with Marilyn, Williams makes the star come alive. She has Monroe's walk, the easy, swivelling neck, the face that responds to everything like a flower swaying in the breeze. Most important, she has the sexual sweetness and the hurt, lost look that shifts, in a flash, into resistance and tears." The critic called the film "charming and touching" and said it is expertly made. Writing for Time, Mary Pols called My Week with Marilyn "nothing more than a lively confection." Pols went on to say "Williams locates a central truth, the contradictory allure of this utterly impossible woman — mercurial, vain, foolish, but also intelligent in some very primal way and achingly vulnerable." Upon giving the film three and a half out of four stars, critic Roger Ebert said "What matters is the performance by Michelle Williams. She evokes so many Marilyns, public and private, real and make-believe. We didn't know Monroe, but we believe she must have been something like this. We're probably looking at one of this year's Oscar nominees."
Manohla Dargis of The New York Times thought Branagh was miscast as Olivier, but she said he made up for that with "his crisp, at times clipped, enunciation and a physical performance that gives Olivier enough vitality so that when, early in, the character sweeps into his production office with his wife, Vivien Leigh (Julia Ormond, a wan placeholder for the original), he dazzles Clark and jolts this slow-stirring movie awake." Of Williams, the film critic said she "tries her best, and sometimes that's almost enough." Dargis said the main problem is with Hodges' script, which "offers a catalog of Monroe stereotypes." Stella Papamichael of Digital Spy gave the film four out of five stars and she praised many of the cast's performances. Papamichael added "While you won't learn anything new about Marilyn Monroe, you can revel in the silky feel of nostalgia." Empire magazine's Angie Errigo gave My Week with Marilyn three out of five stars and she said "At moments hilarious and others touching, it's a sweet, slight affair, more pretty pageant than pithy biographical drama. Expect awards nominations to stack up for Williams and Branagh." The Wall Street Journal's film critic, Joe Morgenstern was negative about the film saying, "When bad movies happen to good people, the first place to look for an explanation is the basic idea. That certainly applies to My Week with Marilyn, a dubious idea done in by Adrian Hodges's shallow script and Simon Curtis's clumsy direction." Nishi Tiwari of Rediff.com said Williams is "a fascinating watch", but there is nothing about Monroe in the film that we did not know already.