Nick St. Clair is a minor villain from the series Riverdale based on Archie Comics. He is an old friend of Veronica Lodge from her earlier years, and comes to Riverdale with his parents when they attempt to secure a business deal with Nick's father. As Nick "has his father's ear", as Hiram Lodge puts it, it is hoped that Veronica could win him over by playing off of their prior friendship.
When first met, Nick seems charming and affable, but it soon becomes apparent that he has a drug habit, indulging in various kinds of drugs and urging Veronica and her friends to do the same. He takes a shine to the Pussycats and Cheryl Blossom, but at a party that he has with them, Veronica, Betty, and Archie, he peer-pressures several of them into having drugs with him, and after the party ends he makes unwanted advances on Veronica. Despite her insistence that she is with Archie, Nick pushes, and becomes angry when Veronica demands that he stops. In this moment, Nick's true character is revealed as he complains that Veronica always flirted and teased but then never indulged him. He then venomously threatens to sabotage her father's planned business deal with his father if she does not indulge him.
Later at a party being held in celebration of the Lodge's business venture, Nick approaches Veronica pretending to be repentant, but then spikes Cheryl Blossom's drink and takes her off to his hotel room when the drug starts to take effect. Fortunately, Veronica and the other Pussycats see this, and, correctly guessing Nick's intentions, pursue. They break into the hotel room right before he can date-rape Cheryl, and kick him into submission.
Later, when being blackmailed by The Black Hood into giving him the name of a guilty person to kill in lieu of her family, Betty (with some reluctance), names Nick St. Clair. She then in the following episode runs to the hotel to make sure the Black Hood has not yet killed him, arriving moments before the police do to arrest him for his rape attempt. However, Penelope Blossom cuts a deal with the Lodges to keep the case from going to trial, something Nick later rubs in Cheryl's face at Pop's Diner, confident that he will walk. As Veronica and Josie had earlier taken drugs that stay in their system for a few days, they are considered unreliable as witnesses, and so cannot testify against Nick on Cheryl's behalf. That is, until Veronica admits to her parents that Nick attempted to force himself on her, something she had been hesitating to do for fear her father would murder Nick in retaliation. The Lodges then cease their dealings with the St. Clairs, rendering their reason for keeping Nick out of a courtroom null and void. Simultaneously, Penelope decides to reject the check of hush money, having by then reconciled with her daughter.
At the end of the episode, it is revealed that the St. Clairs had an "accident" whilst in their car, with it being strongly implied that the Lodges arranged it in retaliation for Nick's attempted rape of their daughter. Nick survives, but is said to now be hospitalized, and that it will take him some months to recover. Pleased that Nick got some amount of karma for his actions without her parents killing him, Veronica notes: "Oh well. Karma's a bitch".
- Nick represents the second villain in Riverdale who initially appears an affable and charming young man with an interest in Veronica Lodge who is then revealed to be a toxic misogynist who later only pretends to be sorry for previous bad behavior. The first was Chuck Clayton.