Oliver "Ollie" Valentine is a fictional character from the BBC medical drama Holby City, played by actor James Anderson. He first appeared in the eleventh series episode "Proceed With Caution", broadcast on 9 June 2009. Oliver was introduced alongside his older sister, Penny, as a Foundation House Officer 1 (F1) on rotation at Holby City Hospital. Series producer Diana Kyle intended their inclusion to have an "instant impact on the wards." Anderson was selected to play Oliver; he spent time with a real F1 doctor and trained with the programme's medical advisors to prepare for the part. It took him around six months to ease into the role, and a further six to feel comfortable in it.

Persephone "Penny" Valentine is a fictional character from the BBC medical drama television series Holby City, portrayed by actress Emma Catherwood. She appeared from 2009–2011, in the programme's eleventh to thirteenth series. Penny was introduced alongside her younger brother, Oliver, as a Foundation House Officer 1 (F1) on surgical rotation at Holby City Hospital. She eventually progressed to F2 level, before being killed off in the aftermath of a train crash; her death occurring off-screen.