[17] She modelled for teen magazines, such as Elle Girl and CosmoGIRL!, and worked for companies including Fanta, Sony Ericsson, Sunsilk, Urban Outfitters, and Tampax.

[18] She appeared in music videos for artists including The Streets, Westlife, Delta Goodrem, Reuben and Holly Valance and starred as Jake in a scripted reality show called Shoot Me, broadcast on Fashion TV in 2005.

After four years, Chung quit modelling with the intention of stidying an art foundation or fashion journalism course, having become disillusioned with her career.

In September 2008, Chung walked the catwalk as part of the Vivienne Westwood Red Label Spring/Summer 2009 show at London Fashion Week.

[21] She was announced as the first celebrity face of Lacoste in June 2010, appearing in both the TV and print advertising campaigns for their "Joy of Pink" fragrance.

[22] In January 2011, Chung was announced as the face of Italian sneaker brand Superga, in a campaign to mark their 100th anniversary.

[23] In February 2012, she took part in the London Fashion Week show for designer Stella McCartney, where she acted as a guest assistant to magician Hans Klok in a number of illusions including being levitated and sawed in half.

[24][25] Chung worked with Tommy Hilfiger as a guest editor for their Fall 2014 collection, and modeled their clothes.

[29] She frequently appears on best-dressed lists, is a regular model for Vogue, Elle and Harper's Bazaar, and is often seen in the front row at fashion shows.

In January 2010, the designer handbag company Mulberry debuted the "Alexa", a popular bag named after and inspired by her.

[37][38] In March 2022 Chung announced the closure of the Alexachung brand, stating that "the last couple of years have been challenging for small independent businesses and ours is no exception.

"[39][40] In April 2006, the then-model Chung was offered the job of co‑host on Popworld on Channel 4, a music show known for its irreverent and awkward style of interviews.

[42] As well as her work on T4, she became a long-time host of Channel 4's early morning music programme Freshly Squeezed beginning in September 2007.

The live show featured interviews with television and film stars as well as segments devoted to fashion on the red carpet.

[50] She launched her own YouTube channel in May 2019; in a statement, she said: "It's an incredibly exciting prospect as I can't wait to share unfiltered original content through a host of videos spanning fashion, art, travel and other random things.

She then wrote a weekly newspaper column for Britain's The Independent from November 2008 to June 2009, titled "Girl About Town" and later "New York Doll".

She has interviewed designers such as Karl Lagerfeld and Christopher Kane for the publication, and wrote a cover story about Kate Upton.

From 2009 to 2010 Chung was a member of the indie band The Stray with her close friend, model Misty Fox.

[64] In an Instagram post on 28 July 2020, Chung revealed her endometriosis diagnosis and urged more awareness on the disorder.