HolbyBlue (also known as Holby Blue) is a British police procedural drama series that ran for two series from 2007 to 2008. The show revolves around the daily lives of a number of police officers working at Holby South police station. The cast for series one included Jimmy Akingbola as PC Neil Parker, Joe Jacobs as PC William "Billy" Jackson, David Sterne as Sergeant Edward 'Mac' McFadden, Cal Macaninch as DI John Keenan, James Hillier as Sergeant Christian Young, Kacey Ainsworth as Inspector Jenny Black, Richard Harrington as DS Luke French, Zöe Lucker as Kate Keenan, Chloe Howman as PC Kelly Cooper, Kieran O'Brien as PC Robert Clifton, Tim Pigott-Smith as DCI Harry Hutchinson, Sara Powell as Rachel Barker and Elaine Glover as PC Lucy Slater. Velibor Topić and Julie Cox joined the cast in a recurring capacity as drug baron Neculai Stenga and Mandy French, Luke French's wife. By the end of series one, Pigott-Smith and Topic both departed the show. Series two saw the introductions of Oliver Milburn as DCI Scott Vaughan and James Thornton as Constable Jake Loughton. Stephanie Langton took over from Julie Cox in series two to continue playing the role of Mandy.

The series was announced on 27 April 2006, and was created by Tony Jordan as a spin-off from the established medical drama Holby City. The show premiered on 8 May 2007. HolbyBlue ran for two series and was cancelled by the BBC on 6 August 2008, after ratings fell from an initial 5.64 million viewers to a low of 2.5 million viewers. Tony Jordan and Karen Wilson served as the show's executive producers, while Claire Phillips was the producer. Jordan spent time with first serving officers and believed that the key to a successful police drama was its ability to reflect a society "in which it existed". Jordan made the decision to emulate two American police dramas: Hill Street Blues and NYPD Blue. The BBC suggested that Jordan used the "Holby" brand to "create a third arm of the successful Casualty and Holby City format". Jordan questioned whether the series would be "held in disdain" by "soap snobs", but made the ultimate decision to name the drama HolbyBlue after remembering the "joy" he took from "surprising the audience by subverting expectation".

HolbyBlue received mixed reception. Rachel Cooke from The Observer criticised the show's unoriginal characterisation, while The Times' Andrew Billen stated that the most that could be said for the show was that it had a healthy pace, and occasionally well-written dialogue. On the contrary, David Chater from the same newspaper praised the show's "high energy level" and casting. Chater also suggested the show would serve to be strong competition for ITV's police drama The Bill. Jod Mitchell of The Daily Telegraph expressed that the series injected "pace and verve" into the BBC One schedule. Mark Wright from The Stage branded the opening episode of HolbyBlue "boring", with some "duff casting". Wright also criticised the decision to launch the show under the Holby moniker, opining that it is not a true brand as Casualty and Holby City both possess "distinct personalities".

During its lifespan, HolbyBlue was nominated for six awards: Best Drama at the Inside Soap Awards in 2007 and 2008; Best New Drama Series at the TV Quick & TV Choice Awards; actresses Zöe Lucker and Kacey Ainsworth for Best Actress, also at the TV Quick and Inside Soap Awards, and actor Jimmy Akingbola for Best Male Performance in TV at the Screen Nation Awards.

In series one, DI John Keenan learns that his estranged wife, Kate Keenan, is dating a new man. John has sex with senior crown prosecutor Rachel Barker, but quickly regrets his decision to have sex with her. Kate is then employed as a receptionist at the police station, but later attacks Rachel after she is provoked. Kate tenders her resignation, but John manages to convince her to remain at the police station. The pair later reconcile. DS Luke French works with John to take down drugs baron Neculai Stenga. DCI Harry Hutchinson acts as Neculai's informant, but John is convinced that PC Billy Jackson is the informant. John later learns that Harry is Neculai's informant after catching him leaving Neculai's warehouse, which leads to a hostage situation involving Kate and her children. John and Luke rescue Kate and the children; although they are shot in the process, they both survive. Newly appointed PC Lucy Slater is stabbed while out on duty. She recovers, and begins dating a drug dealer. Her former partner, PC Robert Clifton, learns of Lucy's boyfriend's criminal reputation and forces the pair to separate. DS Luke French and his wife, Mandy French, fail their second attempt at IVF. Luke and Mandy argue over Luke's divided priorities between her and his terminally ill mother. Luke agrees to put his terminally ill mother in a care home, but is later heartbroken when she dies following a fall. PC Kelly Cooper struggles with her financial difficulties and considers stealing money she finds while out on duty. Inspector Jenny Black ends her marriage with her husband, Alex Black, when she learns he is having an affair. PC Neil Parker is offered a promotion, but he is dismayed upon learning it is political as opposed to merit-based.

In series two, well-established Holby City character Jac Naylor is arrested on suspicion of the murder of Alan Clooney, a well-known sex offender who tried to rape her. She is later released when a mystery witness comes forward. Luke becomes a father for the first time with wife Mandy; she later dies unexpectedly after a roadside incident. Kate flirts with a man she finds at a police event, only to later learn she has been flirting with new boss, DCI Scott Vaughan. Robert is encouraged by Lucy to ask an ex-girlfriend of his to see their son. Robert's ex agrees to allowing him to see their son at the end of his shift. However, while Robert and Lucy are out on duty, gang violence results in the death of one of the gang members. Robert and Lucy visit the relatives of Connor in the aftermath of his death, where Robert is murdered by the victim's brother. John goes to visit his father in jail, which strains his relationship with Kate. It later transpires that John's father was imprisoned for abusing prostitutes. Neil develops feelings for Kelly and inadvertently reveals them to her. Kelly later tells Neil that she is not interested in him, and nothing will develop between them.

The BBC announced the creation of HolbyBlue on 27 April 2006. The newly-proposed drama was revealed to be a police spin-off from medical drama Holby City. It was also confirmed that Tony Jordan had been recruited to work on the scripts and consider "how storylines between the police station and the hospital could be intertwined for the programme." Three production companies were involved in the development of HolbyBlue: BBC, Kudos and Red Planet Pictures. The Guardian picked up on the BBC's reverse tactic of creating a police procedural spin-off drama from a medical drama, compared to ITV, which "spawned a hospital spin-off", The Royal, from original police procedural drama, Heartbeat.

Upon being approached by the BBC to develop a new police procedural drama, Jordan explained that he was conflicted between emulating the former BBC police drama Dixon of Dock Green, using "a set of flawless characters roaming the streets dispensing justice and words of wisdom", or creating a more modern drama, developing characters who would "snort a line of coke, beat up the missus on the way out and shag each other in the locker rooms". Jordan went on to research his new project by spending time with first serving officers, who "portrayed a world of endless, statistic-led red tape". After spending time with first serving officers, Jordan concluded that he was left with an image "not of a modern-day police force, fighting crime on the streets and keeping us all safe, but some kind of unwieldy, top-heavy administrative process, more concerned with public opinion than dispensing justice."