Holby City is a medical drama currently airing in the UK. It consists of 19 series and began airing in January 1999. It is the sister show of Casualty, and is set in the same fictional town of Holby.

Characters from Holby City such as Guy Self, Henrik Hanssen Jac Naylor and Zav Duval have made guest appearances in Casualty more recently. With characters from Casualty such as Ethan Hardy, Iain Dean, Jez Andrews and Connie Beauchamp making guest appearances in Holby City. In addition, Adrian "Fletch" Fletcher was previously a main character on Casualty but transferred to Holby City. This then happened again but with former main character Lofty.