Nico Blake (also Bradley) is a fictional character from the British Channel 4 soap opera Hollyoaks, played by Persephone Swales-Dawson. The character made her first screen appearance during the episode broadcast on 6 June 2014. The character and casting was announced on 20 May 2014. Nico is the daughter and niece of established twins characters Dodger Savage (Danny Mac) and Sienna Blake (Anna Passey), the adoptive daughter of Sienna's boyfriend Ben Bradley (Ben Richards), and the granddaughter of Sienna and Dodger's parents Jeremy Blake (Jeremy Sheffield) and Anna Blake (Saskia Wickham) and the niece of their half-brother Will Savage (James Atherton) and their half-sister Liberty Savage (Abi Phillips/Jessamy Stoddart), and a half-sister and cousin of Dodger's daughter Myra-Pocahontas Savage-McQueen.

Nico's prominent storylines include: a fraught relationship with Sienna and Patrick; kidney failure from the "End of the Line" train crash; discovering that Dodger is actually her biological father; a relationship with Dylan Jenkins (James Fletcher); accidentally killing Ben's daughter, Carly Bradley (Sophie Wise) with a paperweight; her crush on Jason Roscoe (Alfie Browne-Sykes) and stalking his girlfriend Holly Cunningham (Amanda Clapham); coldly murdering Patrick, who is terminally ill, by smothering him; attempting to murder Theresa McQueen (Jorgie Porter) for her kidney; pushing Will off the hospital roof; stabbing Sienna; suffering a heart attack when she requires another kidney transplant; murdering Dylan's father Trevor Royle (Greg Wood) by stabbing him on his wedding day to Grace Black (Tamara Wall); bullying cancer patient Jade Albright (Kassius Nelson) with her friend Peri Lomax (Ruby O'Donnell), whom she later develops an unhealthy obsession with and holds hostage.

Nico was seemingly killed off on 1 November 2016, as part of the show's "Halloween Spooktacular" episodes. Nico becomes trapped in a maze by a fire and fallen debris after a final showdown with Sienna, which was caused by Peri's father, Cameron Campbell (Cameron Moore), after he discovers Nico's psychotic tendencies. She made an unannounced return on 15 May 2018, when she was revealed as Sienna's stalker. Following her return, her storylines included seemingly killing Sienna, however Sienna faked her own death in order to catch Nico; revealing herself to be heavily pregnant; attempting to kill Peri's friend Harley Frater (Mollie Lambert); holding Peri and Harley hostage; giving birth to her daughter and being killed by Sienna in self-defence. In 2020, Nico made several appearances as hallucinations to Liberty, who struggles with postnatal depression after giving birth to Faith.

The casting of Nico was announced on 20 May 2014. Daniel Kilkelly from Digital Spy reported that Nico arrives in Hollyoaks and meets Dodger Savage (Danny Mac). He takes pity on her and gives her food. A show spokesperson added "Is this girl just a passing tearaway teenager? Or could tihere perhaps be something more?" It was soon announced that Nico is the long-lost daughter of Sienna Blake (Anna Passey). But Patrick Blake (Jeremy Sheffield) intervenes to ruin Nico and Sienna's chances of becoming acquainted. His scams include paying Nico's adoptive mother Denise (Janet Bamford) to trick Sienna into believing someone else is her daughter. When Nico tells Sienna that she is her daughter she is dismissed as a liar. This prompts Nico to begin a revenge campaign.

According to Channel 4's official Hollyoaks page Nico is "intelligent, funny, but with quite a dark streak", as well as being quite mature for her age, as a result from going to care home to care home. It also mentions that although Nico has a tendency to push people away, this is down to a fear of rejection and in reality she just wants "to be loved and to be a part of a real family" and that she is "looking for a place in the world."

In an interview at the British Soap Awards 2015, Anna Passey commented that Sienna had "spawned a devil child". It was also noted by Daniel Kilkelly, that Nico would begin to show a dark streak. This was later confirmed to be true, when Sienna confronted her regarding the murder of Carley, Patrick and Trevor, Nico refused to believe that she had done anything wrong, demonstrating true psychopathic behaviour. Persephone Swale-Dawson later commented that Nico was developing a "sinister streak."

Nico arrives in the village as the long-lost daughter of Sienna Blake. Although she knows that Sienna is her mother, Sienna believes otherwise due to her being told by her father, Patrick, that her daughter is someone else. Although Sienna, initially disbelieves Nico, she starts investigating her claim after suspecting that she has something to do with Nancy Osborne (Jessica Fox) finding out about her new job, which leads to Sienna finally recognizing that Nico is her daughter.

Upon their reunion, Anna Passey noted that their reunion wasn't what Sienna was expecting, and that when she finds out that Patrick threatened Nico to stay away, Sienna would be heartbroken. Passey also commented how both characters would have an interesting time ahead of them as neither of them is what the other one was expecting, with Passey noting how Sienna isn't "necessarily mum material!" Hollyoaks producer Bryan Kirkwood also refused to answer whether Sienna and Nico would be able to keep their happily ever after.