The third series of the British medical drama television series Holby City commenced airing in the United Kingdom on BBC One on 5 October 2000, and concluded on 5 June 2001.
Following its second series run of 16 episodes, the third series of Holby City ran for an extended 30 hour-long episodes. The series initially aired on Thursday nights on BBC One, before moving back to its original Tuesday night timeslot. The show's scope was expanded with the addition of a children's ward, allowing for greater diversification in patient storylines. While the series was in production, creator Mal Young deemed Holby City "the first successful new BBC1 one-hour drama format", in contrast to the failed programmes Harbour Lights and Sunburn. Although Young had once favoured soap opera stars in his casting, he reversed his position, explaining: "We're all guilty of grabbing a face, but it's a short-term gimmick. Viewers see right through it. It's the scripts that count. On the other hand, the soaps are so prevalent it's hard to find someone who hasn't been in one."
Matt Wells and Maggie Brown of The Guardian opined in September 2000, while the series was in production: "Series such as Holby are what the BBC really needs, the fresh but reliable mid-week regular drama that ITV is best at."