She is best known for playing Charlotte Hinchcliffe on the E4 comedy series The Inbetweeners (2008-2010), and for her roles in Keith Lemon shows, such as Lemon La Vida Loca, The Keith Lemon Sketch Show, and The Keith & Paddy Picture Show.
Atack appeared on the fifth series of Dancing on Ice in 2010. She was runner-up on the eighteenth series of I'm a Celebrity...Get Me Out of Here! in 2018, and went on to co-present the final series of its spin off show I'm a Celebrity: Extra Camp in 2019. Since 2020, she has starred in her own comedy series The Emily Atack Show.Aside from The Inbetweeners (Channel 4), Atack has appeared in films such as the remake of Dad's Army opposite Catherine Zeta-Jones and Bill Nighy. She appeared alongside Harvey Keitel and Gabriel Byrne in the British film Lies We Tell, and has performed in television programmes such as Rock and Chips (BBC), Little Crackers (Sky1), The Keith Lemon Sketch Show (ITV2) and Tracey Ullman's Show (BBC).
Atack was a contestant on Dancing on Ice in 2010. She was partnered with professional ice skater Fred Palascak; they were voted off in the eighth week. In 2011, Atack presented a stylised public service announcement titled Ready, Steady, Drink, highlighting the dangers of drinking alcohol.
On 12 November 2018, Atack was confirmed to be participating in that year's series of I'm a Celebrity...Get Me Out of Here! She eventually finished in second place behind Harry Redknapp. She released her first book, Are We There Yet?: To indignity ... and beyond!, on 31 October 2019. In November 2019 she began co-hosting I'm a Celebrity: Extra Camp alongside Joel Dommett and Adam Thomas.
In 2020, Emily Atack starred in a new series called The Emily Atack Show, featuring a mixture of stand-up comedy, impressions, and stories about her life experiences including dating, relationships and the pressures of social media and fame.