Peter Barlow is a fictional character from the British ITV soap opera Coronation Street, played by Chris Gascoyne from 2000 to 2023. The character of Peter was born on screen during an episode broadcast on 5 April 1965, he was born along with his twin sister Susan (Katie Heanue, Wendy Jane Walker, Suzy Patterson, Joanna Foster) to parents Ken (William Roache) and Valerie Barlow (Anne Reid). Gascoyne made his first appearance in the role during the 40th anniversary live episode airing on 8 December 2000. Gascoyne left the role in 2003 and returned in 2007 for a brief stint before returning full-time in 2008. In January 2014 it was confirmed that Gascoyne would be leaving once again. His final scenes aired on 14 November 2014. In April 2015, it was announced that Gascoyne would reprise the role for two episodes for the funeral of Deirdre Barlow (Anne Kirkbride) and Peter returned on 15 July 2015 and left once again the following day. In July 2016, it was announced that Peter would be returning as a regular character, with his return airing on 17 October 2016. Peter departed the series again on 26 December 2023. Peter made a voice appearance on 24 January 2024. Peter's storylines have included a number of affairs, alcoholism and a custody battle involving his son Simon Barlow (Alex Bain). Peter became involved in a bigamy storyline when he married Rovers barmaid Shelley Unwin (Sally Lindsay) and florist Lucy Richards (Katy Carmichael). Having been discovered, Peter was left alone and fled Weatherfield. He returned briefly in 2007 when his adoptive sister Tracy Barlow (Kate Ford) was sentenced to life imprisonment for the murder of Charlie Stubbs (Bill Ward). He returned for good in 2008 with five-year-old Simon, whom he had by Lucy; who had since died from breast cancer. Peter began a relationship with Leanne Battersby (Jane Danson) and they married during the 50th anniversary episode; however, they divorced in 2012 after Peter's affair with Carla Connor (Alison King) was discovered. Peter later went on to marry Carla, and then had an affair with much younger Tina McIntyre (Michelle Keegan). Peter was framed for Tina's murder by Rob Donovan (Marc Baylis) and upon his release from prison, his marriage to Carla broke down and he left Weatherfield.

When he returned in 2016, it was revealed he had begun a relationship with Toyah Battersby (Georgia Taylor), which they agreed to keep secret from a pregnant Leanne, in order to not affect her pregnancy. Simon and Leanne's sister Eva Price (Catherine Tyldesley) soon discovered this, followed by Leanne, and he and Toyah subsequently purchased The Rovers Return, from Steve McDonald (Simon Gregson). He and Toyah soon begin family planning, with them beginning surrogacy, as Toyah had multiple failed IVF treatments in the past and was unable to conceive naturally. Their baby son was stillborn, and Toyah and Eva secretly agreed to pretend that Eva and Aidan's daughter, Susie, is Peter's daughter, as Eva does not want to be a mother, but Toyah tells Peter after Eva has a change of heart, resulting in their split. Afterwards, Peter buys 50% of the Underworld factory from Alya Nazir (Sair Khan), partnering with Carla, and supports Simon after he is the victim of bullying by former friend Tyler Jefferies (Will Barnett), which results in Peter being shot with a paint gun. Peter also sleeps with Abi Franklin (Sally Carman) and supports Carla after the factory collapses after it is sabotaged by builder Gary Windass (Mikey North), which sees Carla blamed for the death of Rana Habeeb (Bhavna Limbachia). Carla has a mental breakdown before the couple reunite into another relationship before later getting remarried in 2021. In October 2023, Peter runs over and kills serial killer Stephen Reid (Todd Boyce).

Robert Heanue was the first actor to portray the character from 1965 to 1970. Chris Dormer played the role from 1970 to 1971 when the 7-year-old actor was written out of the soap due to his parents' emigration to Canada. He did not continue to act and reflected on his time as the young Peter in 2001, "I really enjoyed the Street. I remember Pat Phoenix and Julie Goodyear kissing and tickling me because they thought I was cute. Most of the actors were nice, but some weren't. Violet Carson, who played Ena Sharples, was very grumpy. She didn't like children and really scared me." On-screen Peter and his sister Susan were written out of the soap to live with their grandparents when their mother Valerie Barlow was killed off.

One of the seven actors who has portrayed the character is Linus Roache, the real-life son of William Roache who portrays Peter's father, Ken Barlow in the programme. Linus returned to the show in 2010, playing Lawrence Cunningham, another son of Ken Barlow.

Upon the character's return to the show in October 2008, Chris Gascoyne spoke of his character's destructive personality in an interview with Digital Spy, he stated, "He's been trying against the odds to sort his life out, but he can't. And when it doesn't work and it all goes wrong for him, he has a drink. There are hurdles in his way all the time. He's stubborn and resents people telling him what to do. He'll listen to advice, but he won't take any notice if he thinks the person giving it isn't in a place to do so. That happens a lot with Ken."

Peter returns to Weatherfield with his recently discovered son, Simon Barlow (Alex Bain), and Leanne helps Peter as he struggles with fatherhood. Leanne is still "reeling" after her ex-boyfriend, Dan, ends their relationship. Peter returns to Weatherfield a "broken man" and finds fatherhood difficult. Gascoyne told Digital Spy that Peter has not thought about how his relationship with Leanne is progressing. Gascoyne explained that Peter is taking it "step by step", saying "Peter knows that Leanne gets on really well with Simon and I think Peter's nicely surprised by that. Leanne kind of has the upper hand on him and in a strange way, Leanne's a moral voice."

In December 2008, Gascoyne revealed that an upcoming storyline would see Peter enter a rehabilitation facility for his alcohol dependence. Leanne tells Peter's family that she is going to reconcile with him rather than accept a job offer from her friends in Leeds. However, a woman named Christina (Sarah-Jayne Steed) arrives and claims that she met Peter on her father's yacht recently and decided to visit him. Leanne discovers that Peter left rehab early and she decides to leave. The story arc was implemented to facilitate Danson's temporary departure from the show to take maternity leave. Digital Spy reported that Leanne becomes "fed up" with Peter taking her for granted and finds employment in a restaurant in Leeds. Peter attempts to prevent Leanne from leaving by getting Simon to beg her to stay. Despite this, Leanne leaves for Leeds. Leanne's departure was broadcast on 9 March 2009. Leanne made her full-time return on 11 September 2009 when Peter finds her in Leeds. Peter and Leanne later reunite their relationship.

After Peter becomes disabled, Gascoyne said that Peter will be unable to be a proper husband to Leanne. Leanne and Peter's wedding day is coming closer, and Leanne is still having an affair with Nick. When asked to sum up Peter and Leanne's twelve months of marriage, Gascoyne said: "It's been very rocky to say the least. There was the stuff with Nick, Peter was very ill and had to get back on his feet, and there was all the guilt of Ashley dying, so it started off badly and carried on badly. And Peter says he's forgiven Leanne for Nick, but in his heart, it still niggles him." Danson said: "It's not been the best, has it! They had the blessing, where Peter found out about Nick, and then her mother turned up and they argued over that, then she got pregnant and had about half an episode of happiness, and then she lost her baby. And in the middle of all this, Carla's been hovering in the wings..." It was announced in September 2010 that Peter's father, Ken, will catch Leanne in bed with Nick. An insider commented: "Leanne is wracked with guilt over the affair," a source told the paper. "She loved Peter, she loves his son Simon and they've been through a lot together – but Nick was her first love and she never got over that." It was later revealed that Peter will find out from his sister Tracy Barlow (Kate Ford) that Leanne is sleeping with Nick.