[2][3][4] Hamm also acted in lead roles in the films Stolen (2010), Million Dollar Arm (2014), Keeping Up with the Joneses (2016), Beirut (2018), and Confess, Fletch (2022), as well as his supporting roles in The Town (2010), Sucker Punch (2011), Bridesmaids (2011), Baby Driver (2017), Tag (2018), Bad Times at the El Royale (2018), The Report (2019), Richard Jewell (2019), No Sudden Move (2021), and Top Gun: Maverick (2022).

[23] Hamm admitted the crime as part of a deferred adjudication plea deal and the charges were dismissed following the completion of probation.

[25] After graduating in 1993 with a Bachelor of Arts degree in English,[24] Hamm returned to his high school to teach eighth-grade acting.

[30] He decided that his 30th birthday would be his deadline to succeed in Hollywood,[19] and has said: You either suck that up and find another agent, or you go home and say you gave it a shot, but that's the end of that.

[20]In 2000, Hamm landed the role of romantic firefighter Burt Ridley on NBC's drama series Providence.

[19] His career was bolstered by his recurring role of police inspector Nate Basso on Lifetime's television series The Division from 2002 to 2004.

[32][33] Other minor roles followed on the television series What About Brian, CSI: Miami, Related, Numb3rs, The Unit, and The Sarah Silverman Program.

[36] Hamm landed his breakthrough role in 2007, when he was chosen from over 80 candidates[30] to play Don Draper, protagonist of AMC's drama series Mad Men.

In the series, set in a fictional 1960s Madison Avenue ad agency, he played a suave, married, philandering executive with an obscure past.

[11][39] Hamm says that he used memories of his father to portray Draper, a well-dressed, influential man of business and society[18] hiding great inner turmoil[11] and experiencing changes in the world beyond his control.

[51] Hamm hosted Saturday Night Live, season 34, episode 6, on October 25, 2008,[52] and played various roles, including Don Draper in two sketches.

[54][55] In 2009, he guest-starred in three episodes of the NBC television sitcom 30 Rock as Drew Baird, a doctor who is a neighbor and love interest of Liz Lemon (Tina Fey) earning three nominations for the Primetime Emmy Award for Outstanding Guest Actor in a Comedy Series.

[56][57] Hamm's first leading film role came with the independent mystery thriller Stolen in 2009, in which he played a police officer whose son has been missing for eight years.

[61] After receiving "about 40 scripts that were all set in the 60s, or had me playing advertising guys," Hamm was pleased that The Town offered him a role that was "the opposite to Don Draper.

[64] His next acting role was as defense attorney Jake Ehrlich in the independent film Howl, based on Allen Ginsberg's eponymous 1956 poem.

Hamm and Westfedlt acted alongside Adam Scott, Kristen Wiig, Maya Rudolph, and Megan Fox.

He had a recurring role in the sitcom The Increasingly Poor Decisions of Todd Margaret in 2012, as the servant of sociopathic billionaire Dave Mountford (Blake Harrison).

"[74] He had a number of roles in 2015, including the comedy show Unbreakable Kimmy Schmidt and Wet Hot American Summer: First Day of Camp.

[85] Hamm appeared in the BBC and Amazon's 2019 television adaptation of Terry Pratchett and Neil Gaiman's Good Omens as the Archangel Gabriel.

[86] From 2020 to 2021, he played himself in a recurring role in the HBO comedy series Curb Your Enthusiasm, appearing opposite Larry David.

The same year, Hamm reunited with Greg Mottola on their second collaboration and his Mad Men co-star John Slattery for Confess, Fletch.

The following year he joined the Apple TV+ drama series The Morning Show, appearing alongside Jennifer Aniston and Reese Witherspoon.

Hamm appeared in the second series, released in 2023, of Amazon's television adaptation of Terry Pratchett and Neil Gaiman's Good Omens, reprising his role as the Archangel Gabriel.

[89] In 2024, Hamm collaborated with Tina Fey acting in the movie musical adaptation of Mean Girls playing Coach Carr.

[95] In 2013, American Airlines debuted a television commercial titled "Change is in the Air," featuring Hamm's voice-over.

[99] Also in 2022, Hamm was featured in a series of TV commercials for Progressive Insurance as having an off-and-on relationship with spokesperson Flo.

[110][111][112] Osceola briefly appeared as the flower child receptionist at the California coastal retreat that Hamm's character stayed at in the 2015 series finale of Mad Men.

[119] In 2014, Hamm, Kerry Washington, and Kevin Love appeared in a PSA for stopping sexual assault on college campuses.

[122][123] In January 2024, Hamm endorsed Adam Schiff in his bid for the 2024 United States Senate elections in California and sent a political fundraising email on his campaign's behalf.