Dee first became well known to audiences in the early 1990s. During that decade he appeared in a series of high-profile adverts for the brewery John Smith's in which he introduced the recently invented widget.

Dee has presented a variety of television shows on the BBC, the first of note being The Jack Dee Show in 1997. His recent TV programmes have included Jack Dee's Happy Hour ("it's not happy and it doesn't last an hour"), which ran for two seasons in 2000 and 2001 and most recently Jack Dee - Live at the Apollo which aired in late 2004 (A second series followed in the Autumn of 2005). Each episode of Live at the Apollo featured a half-hour performance from a well-known British or international comedian, with Dee introducing and concluding each programme. Guests included Jo Brand, Ross Noble, Ardal O'Hanlon, Joan Rivers, Omid Djalili, Marcus Brigstocke, Julian Clary, Rob Brydon, Rich Hall, Lee Mack, and Dara O'Briain. Dee also regularly works with Comic Relief.

A regular feature of Dee's stand-up performances involves members of the audience leaving messages for him during the show, to be read out, with his responses, during the end. This has occurred in the past with pen and paper; in episodes of Live at the Apollo Dee gave out his mobile phone number that the audience could text messages to.

Dee has also had some success as a straight actor, notably in an episode of the BBC drama series, Silent Witness. On 16 March, 2001, he showed another side of his character, endeared himself to viewers and was the winner of the UK's first Celebrity Big Brother. Dee does not look back fondly at his Big Brother experience, and in January 2006 he was one of only two participants to refuse to allow archive footage of his time in the house to be used in a retrospective documentary about the first three series.