In addition to playing sports (including volleyball, badminton, and soccer),[24] she was on the student council, participated in the Crime Stoppers program, and was a member of the Peer Helping Team.

[32] In 2001, McAdams made her television debut in the MTV pilot Shotgun Love Dolls as Beth Swanson, which was filmed during March break from York University.

[35] Afterwards, McAdams returned to Canada to star as Kate McNab in Slings and Arrows, a comedy mini-series about backstage theatre life at the fictional New Burbage Shakespearean Festival.

[37] McAdams's break-out role came in 2004, when she starred in the comedy film Mean Girls opposite Lindsay Lohan, Lacey Chabert, and Amanda Seyfried, based on Rosalind Wiseman's book Queen Bees and Wannabes.

McAdams was 24 years old when she was cast as the mean high school queen bee Regina George, and she modelled her character on Alec Baldwin's performance in the drama Glengarry Glen Ross (1992).

[54] Michael Wilmington of the Chicago Tribune declared her "a real discovery" who "infuses young Allie with that radiant, breathlessly winning ingénue grace and charm that breaks hearts".

[71] Robert Koehler of Variety found her "increasingly impressive"[72] while Roger Ebert of the Chicago Sun-Times asserted that "she brings more presence and credibility to her role than is really expected; she acts without betraying the slightest awareness that she's inside a genre.

"[84] During that period, McAdams turned down roles in the films The Devil Wears Prada (2006), Casino Royale (2006), Mission: Impossible III (2006), Iron Man (2008),[85] and Get Smart (2008).

[91] Todd McCarthy of Variety criticized her break from the big screen but felt that, despite a performance of "tender feeling", "her natural vivaciousness and spontaneity are straitjacketed" by the film noir format.

[95] The film also had a limited release and Laura Kern of The New York Times found her "luminous as always"[96] while Roger Ebert of the Chicago Sun-Times hailed the performance as "her coming of age as an actress".

[99] In 2009, McAdams starred with Russell Crowe, Helen Mirren and Ben Affleck in the political thriller State of Play, based on the BBC drama television series of the same name.

[101] Gleiberman of Entertainment Weekly felt she was "perfectly cast as an ambitious wonkette"[102] while Sukhdev Sandhu of The Daily Telegraph noted that "McAdams, with her lively eyes and large, expressive forehead, holds her own against Crowe.

[105][106] McAdams fell "madly in love" with the novel,[107] but was initially slightly hesitant to accept the role because she felt Clare Abshire, the long-suffering wife, was a "character that people have already cast in their heads".

[123] While Manohla Dargis of The New York Times felt she "plays her role exceptionally well" and is "effortlessly likable", it called on Hollywood to give her parts "worthy" of her talent.

[64] In 2011, McAdams starred in Woody Allen's fantasy romantic comedy Midnight in Paris with her Wedding Crashers co-star Owen Wilson and Michael Sheen.

"[140] Joe Morgenstern of The Wall Street Journal felt "she vanishes all too soon in this overproduced, self-enchanted sequel, and so does the spirit of bright invention that made the previous film such a pleasant surprise.

[146] A. O. Scott of The New York Times stated that "the dimply and adorable Rachel McAdams" brings "enough physical charm and emotional warmth to distract from the threadbare setting and the paper-thin plot".

"[166] The following year, McAdams starred opposite Philip Seymour Hoffman in an adaptation of John le Carré's espionage thriller A Most Wanted Man, directed by Anton Corbijn.

[170] Richard Lawson of Vanity Fair noted that McAdams had a "little less success with her accent" than her co-star Hoffman but, nonetheless, she "proves as intelligent, soulful, and magnetic a presence as ever".

[172][173] In 2015, McAdams starred with Michael Keaton, Mark Ruffalo and Stanley Tucci as journalist Sacha Pfeiffer in Tom McCarthy's Spotlight, a drama about the child-abuse scandal in Boston's Catholic Church.

Though Justin Chang of Variety felt McAdams imbued her character with "sensitivity and grit", he was nonetheless surprised by her subsequent Academy Award nomination: "[The performance] has the sort of fine-grained subtlety that voters too rarely notice.

Take another look at that scene in which she gently, skillfully encourages an abuse survivor to lay bare his most lacerating secrets—a small master class in how the simple act of listening can become a conduit for compassion.

[182] While the film received a negative reaction and controversy from critics and audiences alike,[183] Wesley Morris of Grantland remarked: "Someone who can speak Crowe's language really helps.

[188] Guy Lodge of Variety remarked: "Poor McAdams, sporting sensible hair and a truly mystifying cod-Continental accent, continues her thankless run of needy, tossed-aside love interests in big-name auteur projects.

Ani Bezzerides in the second season of HBO's anthology crime drama True Detective with her Wedding Crashers co-star Vince Vaughn, Colin Farrell and Taylor Kitsch.

[190] Richard Vine of The Guardian remarked: "If there's anyone with any chance of enjoying a McConaughaissance here it's probably McAdams – an actor whose characters are more usually associated with the death of the romcom than murders involving people with eyes burned out by acid.

[192] The following year, McAdams voiced The Mother of The Little Girl in an animated version of The Little Prince,[193] and co-starred with Benedict Cumberbatch in the Marvel Cinematic Universe superhero film Doctor Strange.

"[198] Richard Lawson of Vanity Fair felt her character lacked "any real arc or motivation of her own", but "It's a testament to McAdams's talent and charm, then, that she doesn't get lost in the movie, asserting herself in every scene with a goofy brightness.

Vanity Fair's Richard Lawson wrote in his review that McAdams "deftly paints a thorough and compelling picture of a woman of the era" in her portrayal of the titular Margaret's mother, Barbara.

[212] Variety noted that McAdams' "projection was muted at a recent performance" but added "[She] masters her portrayal of a determined caregiver continually sitting in the uncertainty of worry, despite constantly leaning toward positivity.