| Holby City | |
|---|---|
| Series 21 | |
 The Series 21 Cast Image | |
| No. of episodes | 53 |
| Release | |
| Original network | BBC One BBC One HD |
| Original release | 2 January – 31 December 2019 |
| Series chronology | |
The twenty-first series of the British medical drama television series Holby City began Airing on BBC One on 2 January 2019 in the United Kingdom. The series consists of 53 episodes. Kate Hall acts as the series producer for episode one and was replaced by Jane Wallbank from the following episode; Simon Harper is the executive producer. The series is billed as an anniversary year for the drama as it celebrates twenty years since its launch. The series also features a crossover episode with sister show Casualty, an episode written by the show's co-creator Tony McHale and the show's 1000th episode, due to be broadcast in November 2019. Thirteen actors reprise their roles from the previous series and former cast members return for guest stints throughout the series. Three new regular characters were also introduced, while Nic Jackman was promoted to the main cast in his role as foundation doctor Cameron Dunn.