Calvin Valentine is a fictional character from the British Channel 4 soap opera Hollyoaks, played by Ricky Whittle. He arrived in July 2006 as a police officer with his mother Diane Valentine, his brother Sonny Valentine and his sister Sasha Valentine and made his final appearance on 21 May 2010 after he was murdered by Theresa McQueen (Jorgie Porter). Whittle was credited for a flashback episode on 1 December 2010. Calvin appeared again as a ghost to tell his wife and Theresa's Cousin Carmel McQueen (Gemma Merna) that his and Theresa's daughter, Kathleen-Angel McQueen, was fine with Theresa in February 2011.

In May 2006, it was announced former Dream Team actor Ricky Whittle would arrive in Hollyoaks as "mysterious" Calvin Valentine. Along with Whittle's casting, it was announced his former Dream Team co-star Jamie Lomas would take on the part of "bad boy" Warren Fox. Speaking of Lomas and Whittle's casting, a Hollyoaks spokesperson stated: "We're delighted to welcome Ricky and Jamie to the Hollyoaks cast. Their characters are set to bring lots of drama to the show!"

In 2009, it was announced that Whittle had decided to leave the series after he quit to pursue other projects. It was then announced that the character would be killed off. Speaking of how he reached the decision to leave, Whittle stated: "To be honest I was always looking to leave next year. It'll be four years next year when I eventually leave. Everyone has ambition. I could stay on this show for the rest of my life because I love it up here - it's a wicked little family and we're all really close. However, I don't want to spend all that time here for a big movie director or producer to come across to England when I'm in my 30s and say, 'If you'd come over when you were in your 20s, you'd've made it really big'. I'd rather go over to the States, go do the movie thing, the drama thing, or even fail - I'd rather go over and fail and have them say, 'You're not good enough, your accent's not right or your look's not right' - at least then I'd know and I'd have it out of my head. I always believe you regret the things you don't do. I don't want what-ifs hanging over me."

Calvin first appeared as an honest, kind-hearted policeman. However, in 2008, the character of Calvin began to change, when his younger sister Sasha Valentine (Nathalie Emmanuel) began buying drugs from Nige Foster (Sam Townend), who Calvin ultimately ended up believing he had killed. Whittle, speaking to Digital Spy, said, "He was at his lowest ebb. Everyone forgets that he's only 22 and he's had to look after his family. He's still just a kid himself and everything piles up on him. He just doesn't know what to do any more. Sasha was on the drugs and then she came off them. Calvin was making an extra effort with her and there was no reason for her to go back to them. He didn't understand why she went back to the drugs after all his efforts. When he caught her 'self-harming' — or what Calvin thought was self-harming — he didn't want her to go through the ordeal, so he went to get her drugs."

Calvin then began dodgy dealings for Warren, including drugs. Whittle, speaking to Digital Spy, said, "Calvin and Warren have always been these stags who have locked horns – good versus evil, battling for the two years we've been on the show together. Warren's going to start corrupting Calvin a little bit. Calvin's been on the moral side for two years and it's not really done anything for him. He's lost the girl, the baby, friends and family. Whereas Warren's been wheeling and dealing and he's got the girl, the club, the money, the car… Let's just say Warren leads Calvin astray a little and they're going to become allies."

The apparent love of Calvin's life was originally Louise Summers (Roxanne McKee). However, their engagement ended when he discovered her affair with his enemy Warren Fox. The second main love for Calvin was Carmel McQueen (Gemma Merna). The characters quickly fell in love, became engaged and eventually married. In May 2008, series producer Bryan Kirkwood, speaking to Digital Spy about the couple's upcoming wedding, said: "They're a fantastic couple to come up with stories for. They're engaged at the moment and it's nice to see the lighter side of Calvin. We'll have fun watching Carmel planning the wedding of the millennium and it'll continue to serve the fun war between the Valentines and McQueens."

Whittle also discussed Calvin and Carmel's relationship and second wedding. He explained: "Calvin's completely besotted with Carmel. She's the one he's always wanted - she's always been his true love since they first started seeing each other and everyone's always wanted them to get back together, which has been nice. I think it's a very good example of fan power. The producers weren't going to put these two together ever again because everyone wanted them together. It was a Ross and Rachel situation — they're meant to be [together], but something would always happen for it not to quite work out. I think Calvin and Carmel fans will be happy that they're back together in the episode — it'll just pull a few heartstrings when Calvin's shot at the end."

Of the flash forward episode in which Calvin is killed, Whittle said: "I was so honoured that they gave me a flash forward — that’s never been done before. So people knew months ago that Calvin was going to die. You want to do a story justice and when it’s your exit, you want it to be memorable." Whittle's final scenes involved his death scene of which he stated: "Calvin was actually already dead, so it was more about the aftermath. I was just lying there while people were crying around me."