Holly and her family are the new tenants of Butlers Farm. Not wanting to be a farm labourer, Holly gets a job at Home Farm and makes friends with Maisie Wylde and studies art at college. Holly persuades Lisa Dingle to become a life model for her art class, after another model drops out. Holly meets Aaron Livesy and they are attracted to each other. When Aaron accuses John of assault, Holly tries to seduce him into dropping the charges but Aaron calls her bluff and asks her to have sex with him. She refuses to do but they later start dating. It doesn't last as Holly thinks Aaron is too clingy and her brother tells her and the rest of the family that he thinks Aaron is gay. Aaron denies it and Holly believes him but ends the relationship soon afterwards.
On a night out, Holly gives Maisie some cocaine. Maisie's mother, Natasha, finds out and sacks Holly, before telling her parents. When John and Moira confront Holly, she tells them she occasionally experiments with drugs. Holly starts taking drugs more frequently with her friend Roz Fielding, who supplies them to her. Holly is expelled from college after she fails to hand in her assignments. John and Moira find out about Holly's expulsion and learn she was dealing drugs. Holly is grounded and forced to work on the farm. She decides to stop taking drugs and earns the trust of her parents again. Vet Rhona Goskirk visits the farm and finds some ketamine missing from her bag. John accuses Holly of taking it and searches her room, but does not find anything. Holly later retrieves the ketamine from Hannah's room, where she hid it, and swaps it for cocaine.
Holly overdoses in a toilet cubicle on a night out and Aaron takes Holly home. Holly begs him to keep her overdose a secret. Holly steals Scarlett Nicholls’ purse to get money for drugs and babysits Viv Hope's children while high. Holly also steals Viv's valium pills and Isaac Nuttall's MP3 player. Moira arranges for Holly to babysit for Laurel and Ashley Thomas's children. Holly invites Roz to keep her company. Roz is disgusted when Holly insists on taking some cocaine. On their return home, Laurel and Ashley become suspicious about Holly's behavior and later find a wrap of cocaine. Ashley tells John and Moira and they manage to persuade him not to call the police. They confront Holly and she blames Roz. Roz becomes angry and tells John and Moira their daughter has a drug problem. When Holly refuses to stop doing drugs, John disowns her. Holly disappears, but later returns to pick up some belongings.
Holly runs into Scarlett in town, but she runs off when Scarlett refuses to give her money. Scarlett sends Holly a text asking if they can meet. Holly discovers she has been set her up, when John appears. He tries to manhandle her into his car, but Holly escapes and runs off. She and her friends later burgle Butlers Farm. Aaron finds Holly working in a bar in Hotten and tells Moira, who turns up and is angered when Holly shows no remorse for what she has done. Moira drags Holly into her car and takes her to the police station, where she asks an officer to arrest her. Moira changes her mind about pressing charges and Holly apologises to her parents. John and Moira later visit Holly at her new address and meet her boyfriend Dan Cravely. Dan throws Holly out, when she cannot pay her way and she returns to the village. Ashley and Douglas Potts find Holly in the graveyard and take her home. Roz comes to visit and Holly asks her for drugs, but Roz refuses to help her.Moira takes Holly to a counsellor, but Holly excuses herself and runs away. She gets some heroin and John and Moira find her collapsed in her room. Holly later has sex with a stranger for money, so she can buy some more drugs. John and Moira decide to lock Holly her in her room and she is forced to go through drug withdrawal alone. The situation begins to affect the whole family. Moira eventually buys some heroin and gives it to Holly, so she can be weaned off slowly. When John offers to take the drug with her, Holly decides to try to get clean. She goes on a methadone programme and gets a job at the factory.
When the Barton's struggle financially, they are forced to sell a car. Holly asks Cain Dingle to get a cheap 4x4 for them and Moira goes along with the plan, paying Cain back in installments. Holly is angry when she learns Moira has been having an affair with Cain and is on John's side. However, when she realises John is flirting with Cain's sister Chas, she forgives her mother and tries to get her back with John. Holly, Hannah and Adam are delighted when John and Moira announce they are back together and they book them a hotel room for a night. They later learn their parents have been in a car accident and they rush to the hospital. Holly is devastated when John dies. Holly tries to be strong for Moira and helps out around the house. She starts to think that John's death was her fault and she purchases some drugs from a dealer. Alex Moss finds Holly in the barn with the drugs and he takes them off of her. Holly asks Alex not to tell Moira about the incident. Cain later finds Holly unconscious at the garage with some drugs beside her and he takes her to the hospital. When she wakes up, Holly tells her family that the incident was a one off and she will not take drugs again. Holly then begins seeing a drugs counsellor again.
In June, Holly becomes disillusioned with her life in the village and decides to move to London to live with Roz, who has got a job there. Holly is also offered a job in designing. Adam is angry and believes that the family should stick together due to their father's death but Holly is adamant that she is going. Hannah decides to join her and after a farewell drinks gathering in the Woolpack, Holly and Hannah bid farewell to Moira and Adam and leave the village in a taxi for the train station.
2016: Return, relapse and recovery Edit
In March 2016, Holly returns and tries to steal Cain's car to cover up her drug addiction fines worth £2,000. Her dealer, Dean, demands she pay up, so Holly has no choice to come back to Emmerdale. Cain is suspicious of Holly, and is quickly proven right when she plans to steal takings from the Woolpack. Charity alerts Cain and Moira, and Cain sees off Dean. A grateful Holly becomes infatuated with Cain, even sabotaging her mother's anniversary plans with him.
In May 2016, Holly kisses Cain and when her mother finds out about it, tries to blame it on him. Facing rejection from Cain and Moira, Holly relapses on heroin. She is found by her cousins Ross and Pete. When Holly is discharged from hospital, Moira tries to send her to rehab, but is told it will take up to 4 weeks for a placement.
In June 2016, Holly ends up getting a new job at Victoria's brand new food van business. Holly's dealer Simon McManus plans a van robbery with her to help pay back her debts, but Victoria inadvertently shows up instead of Holly, and Simon attacks Victoria, leaving her with a bruise on her forehead and a black eye. Victoria loses confidence in herself, leaving Holly guilt-ridden. The following day, a high Holly is driving back to Emmerdale in the van and ends up falling asleep at the wheel of the van. The van ended up swerving to the other side of the road. A car is coming towards Holly in the opposite direction. Holly wakes up again and crashes the van into a wall. Adam pulls up at the van in Moira's car. Adam gets the van back to Holey Scrap because Adam is asked by Victoria to put a padlock on the back door. On Holly's day off, she goes into Hotten to buy some stuff for Victoria thinking it might make her feel safer. A miniature bottle of red runny spraypaints and deafening noise box. Victoria goes into the food van without permission. The back door starts rattling and she gets out the spraypaints, opens the door and opens fire. It is Finn Barton that tried to get in. Holly reads the spraypaint tin and it says it can take up to one week to fade. Cain is suspicious of Holly's behaviour, and insists she take weekly drug tests. Holly panics, but when Cain's young son Kyle is staying over, she uses his urine for her test. Cain continues to doubt her after an instance where she left Kyle alone in the house - she claims she had been accidentally locked out, but doesn't tell Cain and Moira that she had left to recover a packet of heroin she'd thrown into the bins. As Holly continues to seem clean, Moira convinces Cain to stop the tests.
Soon after Cain goes away for a break, the guilt Holly feels over Victoria's continued struggles post-attack lead her to tell Moira the truth. Moira is disgusted, but agrees to help Holly get clean, and to lie for her to Cain, Adam and Victoria. She begins detoxing her at home, but is concerned when Holly isn't getting better. They go to the doctor for methadone. Holly begins to improve, but she disappears from the house one day, convincing Moira that she's gone for drugs. She goes with James to track down Simon at his crack den. During a scuffle, she falls on a needle and realises she might have contracted HIV. She continues to lie for Holly, but Adam and Cain soon learn the truth, leading Adam to wash his hands of them and Moira to end her marriage to Cain. Holly is left feeling responsible and attempts to make things up for her mother.
Holly continues to stay clean and continues with her photography career, getting a job at Take a Vow after Megan decides to give her a chance in spite of lying about her recent relapse. She shoots for the wedding of David Metcalfe and Tracy Shankley, impressing everyone with her work. She is saddened to learn Moira plans to sell up, and she and Adam make peace enough to try to be a united front for their mother. She forms a bond with Jai after meeting him in a support group. Friendship slowly becomes romance. With her professional and personal life looking up, she decides to stay in the village even if Moira moves on.
Holly goes to the village with Moira, where they run into a hung over Cain. Holly tries to convince Cain to win Moira back, but he dismisses her as a "smackhead." At lunch, Jai tells her sometimes love isn't enough to save a relationship. Holly makes plans to go to a friend's wedding, with Jai as her guest. She has also been hired to take the wedding photos. He reassures her worries and tells her he has contacts to help her out; they discuss going public as a couple. Unbeknownst to her, he plans a trip to Paris for the two of them.
Holly wakes Moira up before she leaves for the wedding, telling her she may be better off moving on from Cain, repeating Jai's advice. Moira marvels over how smart and beautiful her daughter has become before they say goodbye.
2016: Death and aftermathEdit
After returning home from the wedding, Holly goes to her room. In the morning, Moira finds the window open and leaves her tea. Some time later, with Holly still not up, Moira checks on her, seeing that she's still wearing her dress and that a heroin wrapper is on the floor. A horrified Moira realises her daughter is dead. Moira and Adam are devastated, as the rest of the village is left mourning and questioning the circumstances of her death. Jai learns the truth from a casual conversation in the factory, and emotionally confesses their relationship to his sister Priya Kotecha.
Moira and Adam search for answers, with Adam planning to kill whoever gave her the drugs. Jai meanwhile decides to stay quiet about his relationship with Holly, fearful of the consequences. Jai eventually tells Moira about their time together, just as Adam sees photographs of them together at the wedding and punches him. Jai convinces them of his innocence, and he and Moira make peace as she asks him to attend the service. Adam tracks down and attacks Simon, who also denies giving her the drugs, insisting he'd never wanted to hurt Holly. A grief-stricken Adam finally accepts that there are no answers. Moira buries Holly in an eco-friendly casket, as she felt her daughter would have wanted.
Just a few weeks after her own death, Holly's uncle James was killed when he was pushed from a walkway and on to the Hotten Bypass by his wife Emma, which in turn caused a huge pile-up and very nearly killed Rhona Goskirk and Holly's friend and ex-boyfriend Aaron Dingle in the process.
In 2011, Holly's drug addiction was nominated for "Best Storyline" at the British Soap Awards. Daily Mirror writer, Tony Stewart, said Holly's drug addiction was "one of the most harrowing" storylines of 2010. He added "With a powerful and moving performance by relative newcomer Sophie Powles, Holly Barton has been transformed from a vivacious young student to a drug-ravaged, emaciated heroin addict over the last few months. Stewart's colleague, Jane Simon, said Holly was a "pretty Anna Friel look-alike."
Holly's death episodes were praised by sites such as Metro and Digital Spy as some of Emmerdale's finest moments.