The film received positive reviews from critics, who praised Fincher's direction, as well as the acting (particularly Oldman and Seyfried), cinematography, production values, and musical score.

The film earned a leading ten nominations at the 93rd Academy Awards, including Best Picture, Best Director, Best Actor (Oldman), and Best Supporting Actress (Seyfried), and won for Best Production Design and Best Cinematography.

Herman dictates the script to his secretary, Rita Alexander, who notices similarities between the main character (Charles Foster Kane) and William Randolph Hearst.

Herman's colleague, director Shelly Metcalf, shoots and kills himself after being diagnosed with Parkinson's disease and guilt-ridden over his role in the smear campaign, despite personally supporting Sinclair.

Herman ultimately receives joint credit with Welles, and they win the Academy Award for Best Original Screenplay for the film (Citizen Kane) two years later.

Many other Hollywood icons are portrayed, including Dolores del Río, George S. Kaufman, Lionel Barrymore, Greta Garbo, Josef von Sternberg, Norma Shearer, Eleanor Boardman, Joan Crawford, Geraldine Fitzgerald, Billie Dove, Rexford Tugwell, Bette Davis, Clark Gable, Charles MacArthur, Darryl F. Zanuck, S. J. Perelman, Carole Lombard, and Eddie Cantor.

[10] Fincher reunites with much of his usual filmmaking team, including production designer Donald Graham Burt, editor Kirk Baxter, and composers Trent Reznor and Atticus Ross, using only period-authentic instruments.

[11][12][13] The 120-page draft of the initial script revealed that Jack Fincher closely followed a claim voiced by Pauline Kael in her 1971 New Yorker article "Raising Kane" that Welles did not deserve screenwriting credit.

"[16] Many current academics and critics were sparked to action by Mank's many-times over debunked premise that the script was Mankiewicz's alone, including NY Times writer Ben Kenigsberg,[17] and Jonathan Rosenbaum, editor of the Welles-Bogdanovich book This Is Orson Welles, who wrote "...Finchers Senior and Junior, willing and eager to accept and further spread Kael's inaccurate assertion that Herman J. Mankiewicz was the only screenwriter on Citizen Kane, not bothering to research the matter.

"[18] Mank producer Eric Roth reportedly polished the script prior to filming,[19] with David Fincher saying he felt early drafts were too anti-Welles.

[23] The film was shot in black and white on Fincher's preferred RED digital camera and made reference to the aesthetics of Citizen Kane cinematographer Gregg Toland.

[2] IndieWire reported the film played in 75 theaters during its opening weekend and did "similar business" as other new indie releases The Climb and Ammonite, which each averaged about $300 per venue (which would mean a $22,500 debut for Mank).

IndieWire wrote that it just "didn't gain the attention of other high-profile originals like Da 5 Bloods, The Trial of the Chicago 7, and Hillbilly Elegy," all of which debuted in first or second place.

The site's critics consensus reads: "Sharply written and brilliantly performed, Mank peers behind the scenes of Citizen Kane to tell an old Hollywood story that could end up being a classic in its own right.

[37] Eric Kohn of IndieWire gave the film a "B+" and wrote: "However much credit Mankiewicz deserves for Kane, Fincher's remarkable movie makes a compelling argument for appreciating the prescience behind its conception.

It's a pleasurably discombobulating experience, sometimes playing like mordant drawing-room comedy and sometimes flirting with expressionist nightmare, as when Welles' dark silhouette looms over a bedridden Mank and his mummified leg.

Brilliantly shot in black-and-white by Erik Messerschmidt, with costumes to die for by Trish Summerville and a period-authentic score by Trent Reznor and Atticus Ross that somehow isn't defeated by the retro mono sound, Mank is meant to match the look and feel of its era, as if it's eight decades ago and you just bought a ticket.

Club's Ignatiy Vishnevetsky thought it was "conventional to a fault", writing that parts of the film "bear an uncanny resemblance to the kind of awards-bait middlebrow drama usually essayed by BBC-trained hacks.