Simon is born in July 2003 to Lucy Richards (Katy Carmichael), who had already split up with Simon's father Peter Barlow (Chris Gascoyne). On learning that he had married his girlfriend, Shelley, when they had married first - she told Shelley that her marriage was illegal. In revenge, Lucy tricked Peter into thinking they had a future together, then, in front of pub regulars, announced she and Simon were emigrating to Australia. Peter resigned himself to the fact that he would never know his son, and left the Street soon after.
Peter is given custody of Simon when Lucy died from ovarian cancer in 2008 and they move in with Peter's father, Ken Barlow (William Roache), Ken's wife Deirdre (Anne Kirkbride) and Deirdre's mother Blanche Hunt (Maggie Jones). Peter, at first reluctant to take an active role in raising his son, changes his mind when he found out that Lucy had left her estate to him, on the condition that he raises Simon. Peter buys the local bookmaker's shop and moves in there, with Simon. Peter drinking problem becomes evident when Peter comes to Simon's Nativity play, drunk and has a row with teaching staff. Simon stays with his grandparents until Peter agrees to stop drinking, but Peter passes out with a lit cigarette in his hand, and the flat caught fire. Luke Strong (Craig Kelly) and Tony Gordon (Gray O'Brien) break the door down, after Deirdre alerts them as Simon had telephoned her before he passed out due to smoke inhalation. Peter and Simon are rushed to hospital and made a full recovery. Peter vows once more to give up alcohol.
Learning that he had a grandson, Peter is surprised to meet Lucy's father, George Wilson (Anthony Valentine). He had separated from Lucy's mother when she was very young and their relationship had suffered but George is determined not to make the same mistake with Simon and Leanne persuades Peter to allow George and his partner, Eve, access. George also invests in the bar that Peter and Leanne intended to open but Ken's worst fears came true when Peter falls off the wagon again and George wins interim custody of Simon. While on holiday in Blackpool. Simon runa away after hearing George tell his wife that he intends to take Simon down to Kent to live and makes his way home alone, scaring everyone in the process. While Peter and Leanne are proud that Simon travelled all that way alone, they made sure he knew that that was very wrong.Simon is devastated when Blanche died. Simon had a fight with Aadi Alahan (Zennon Ditchett) whilst playing a game and Aadi hits his head on a table, leading him to be rushed to hospital when he fell unconscious. Simon does not tell anyone and feels guilty over the incident, while Aadi's parents Dev (Jimmi Harkishin) and Sunita (Shobna Gulati) accuse childminder Claire Peacock (Julia Haworth) of negligence. Simon revealed the truth about Aadi's injury after Peter questions him about his erratic behaviour. Peter tells Dev and Sunita the facts, clearing Claire's name.
Simon is in the Joinery bar when it exploded and causes part of the viaduct to collapse and a tram comes off the viaduct, crashing into the Corner Shop and The Kabin: the results of the destruction brought down a power line (plunging the street into darkness in the process), destroyed the post box and set No.13 on fire. Simon is found at home and rescued by Jason Grimshaw (Ryan Thomas). He is devastated to find his father, Peter, on his death-bed, but relieved when Peter pulled through; his severe injuries left Peter temporarily unable to walk. Simon is thrilled when Peter and Leanne Battersby (Jane Danson) renewe their vows. Simon meets new Rovers manager Stella Price (Michelle Collins) and her boyfriend Karl Munro (John Michie). Stella is revealed to be Leanne's mother at Leanne's 30th birthday. Simon is impressed and Stella later gets him a Nintendo DS game for his 8th birthday. Just before Christmas, Peter begins a clandestine affair with Carla Connor (Alison King), and Simon is devastated when Leanne, learning the truth, leaves the Street. Simon gives Carla a frosty reception when she moves in, insisting that he wants Leanne back and spends as much time as he could at his grandparents' house. Peter, however, does everything he can to make Simon spend more time with Carla, in the hope that Simon will warm to her. Eventually, however, Peter allows Simon to go and live with Leanne, and Peter and Carla leave the country as Peter took an opportunity to sail a yacht from Southampton down to Lanzarote in the Canary Islands.
Simon lives with Leanne and her boyfriend Nick until Peter and Carla return, out of the blue, just as they are about to leave for Las Vegas, where Leanne and Nick plan to get married but Simon now refuses to leave as he wants to see his dad, so they stay. Carla is unhappy as they had only planned to stay in Coronation Street for a couple of days but Peter can't bring himself to leave Simon again so Carla returns to LA alone. Leanne and Nick reschedule their marriage for Christmas Day but after what Peter said on her hen night, Leanne visits Peter and suggests they get back together but Carla has returned and is having none of it! She runs back to the car and plans to marry Nick but before she can say "I do", Eva proclaims what Leanne had done that morning and Nick refuses to go through with the wedding. Simon is devastated and blames Carla. In November 2013, Simon fell victim of a happy slapping attack, orchestrated by Faye Windass (Ellie Leach) and Grace Piper (Ella-Grace Gregoire). He was beaten, forced into a dress and then had lipstick forced over his face. He is later delighted, however, when Peter and Carla hire Tina McIntyre (Michelle Keegan) as Simon's nanny. He confides in Tina about the happy slapping attack, which later leads to Faye and Grace being questioned by the police. Unknown to Carla nor Simon, Peter begins an affair with Tina, which isn't revealed until May 2014.
Carla's brother, Rob Donovan (Marc Baylis), later confronts Tina and attacks her in her own home, leading to an argument on the balcony of her flat. After a scuffle, Rob pushes Tina away, causing her to lose her balance and plummet onto the cobbles below. Tina survives the fall, but Rob later beats her with a metal pipe, when she threatens to tell the police that he tried to kill her. Tina later dies in hospital, devastating Simon, who believes that Peter murdered her. Peter's relationship with Simon thaws a little and he promises him that he did not kill Tina. However, Simon is even more devastated, when Peter is arrested and charged, on suspicion of killing her. When Ken returns from Canada, he persuades Simon to go and visit Peter in prison. He agrees at first, but Rob, wanting Peter to plead guilty, asks Simon if he would like to go to Chester Zoo, with him, Tracy and Amy. Leanne eventually takes Simon to visit Peter, but he does not want anything to do with him, after discovering that he has been drinking. Simon is devastated when Peter ends up in hospital and eventually believes that he did not kill Tina. Maddie Heath (Amy Kelly) begins to babysit Simon and he also shares a bond with Deirdre's dog, Eccles. When Amy thinks that Eccles loves Simon more than she loves her, she tells Tracy that Eccles bit her. Tracy tells Deirdre that she must be put down, but Amy is later forced to tell truth, horrifying Simon. When Rob and Tracy go on a week's holiday in Swansea, Amy's father, Steve (Simon Gregson), asks Ken to babysit Amy for the night, the same night that Deirdre had agreed to babysit Simon. When they arrive together, they immediately clash and when Simon unfolds the sofa into a bed, Amy sits on him. Deirdre, unable to cope with Amy's behavior, sends her back to Steve's house, much to Simon's delight.
After the explosion at Victoria Court, Simon is unaware that his mother's partner, Kal Nazir, has died after saving Amy from the fire. He learns Kal has died from Kal's mother, Yasmeen and Simon is devastated. When Leanne asks Simon to do a simple job whilst sorting out Kal's belongings with Kal's children, Alya and Zeedan, Simon refuses. Simon later storms out of the flat and when he returns, Leanne is annoyed that Simon has eaten and she asks him to wash up. When Leanne tries to talk to Simon about how she knows he has lost his mum, Simon angrily points out she died and he throws a remote at Leanne. Leanne takes Simon to Ken and when asked about the bruise, Leanne lies that it was caused by a cupboard door. Later, Simon apologises to Leanne and Leanne apologises to Simon for what he's been through, but she warns him he can't do what he did again, no matter how angry he gets. The next day, Simon and Leanne go to France to visit Leanne's grandmother Gloria Price to forget about recent events. Simon is later given a shattering blow when he discovers that his grandmother Deirdre died on the day of her 60th birthday and homecoming party.
Simon's behavior and attitude towards Leanneworsens He kicks Leanne on the leg and it causes a severe bleed. Later he shouts in Leanne's face, pushing her and thus beginning to scare her more. After Simon plays a game of football, Leanne says he and some of his friends can come to the bistro for dinner. Simon's friend Kyle peer pressures him into stealing a bottle of vodka, on which Simon and his friends get drunk. Leanne takes Simon home and tries discussing issues, but he walks out. Another row leads to a physical altercation on both sides, Leanne pushes Simon away in self-defence, unfortunately he cuts his arm as he falls to the ground. When Leanne and Simon argue again, Simon pushes Leanne against a table and she is later found unconscious by Dev and Mary and she is taken to hospital, with Zeedan accompanying her. Leanne finally admits to Zeedan what Simon has been doing and Leanne decides to send Simon to stay with Peter in Portsmouth. When Simon returns, his behaviour hasn't improved and he tells Eva Price (Catherine Tyldesley) about his time in Portsmouth and that Peter was too busy with his girlfriend. Eva informs Leanne and when Leanne tries to talk to Simon further about it, Simon storms out. Simon skips school and when Leanne returns home, she finds Simon in the flat with some friends causing chaos. Simon ignores Leanne and walks out and when he comes home, he locks himself in his bedroom. Leanne finally admits to Eva that Simon has been physically abusing her and she doesn't know how much more she can take. When graffiti is sprayed outside the Bistro, Leanne believes Simon is responsible and she later finds a can of red spray paint in his bag. When Leanne confronts Simon, he makes cruel remakes about her infertility and Leanne almost hits him. Leanne arranges for Simon to live with Ken and when Leanne drops Simon at Ken's, Simon tells Leanne that if she walks away, he will never speak to her again, but Leanne leaves him.
When Amy annoys Simon with her violin, he tries to take to violin from Amy, however Ken catches them arguing and they come up with a solution. Simon ignores a text from Leanne, which makes Leanne believe she has lost Simon. Simon arrives home from school early and Robert Preston (Tristan Gemmill) talks to Simon in an attempt to understand how he is feeling. When Simon spots Leanne with Eva looking relaxed, he soon gets angry again. Simon and Amy are left alone at Ken's house and Simon ends up hurting Amy. Amy tells Ken and Tracy, who contact Leanne and Leanne is encouraged by Eva Price (Catherine Tyldesley) to admit Simon has been hurting her. Leanne has to take Simon home and the family agree to get Simon help. Leanne arranges for both her and Simon to see a counsellor. In February 2016, Leanne encourages Simon to do football trials and Simon is successful getting onto the team. On the day of his football match, Simon insists that Leanne doesn't come, however, she does and brings Ken and Zeedan. At the match, Leanne meets Tom (Daniel Casey) again and Simon receives taunts off a fellow teammate. Simon hurts the boy and Leanne is horrified when Simon believes the boy deserved it. After talking to both Ken and Zeedan about her fears, Leanne decides to report Simon to the police. Despite Simon claiming it was an accident, Leanne goes to the police and she is forced to reveal that Simon abused her. The following day, the police visit Simon and Simon is taken to the station with Ken. In the interview, Simon looses his temper and he is later released on bail pending an investigation. Simon refuses to go home with Leanne and decides to stay with Ken. Later, Leanne gets a visit from Tom, who shows them footage of the incident and Leanne realises Simon was telling the truth. Leanne apologises to Simon, but he refuses to forgive her and Simon contacts his dad. Leanne gives Simon the choice of staying with Peter during the half term and he decides to go.
After noticing Leanne has been feeling unwell, Simon confides in Amy about his fears that Leanne has cancer. Amy tries to reassure him, but he finds a message on Leanne's phone confirming a doctor's appointment. Simon goes to the medical centre and wants Leanne to tell him what is wrong. At home, Leanne tells him she is pregnant. Leanne avoids telling Simon about the baby's father and he buys a baby grow. Leanne reassures Simon that he is her first child and she won't love him any less. Leanne decides to move to Liverpool with Simon. Simon takes a set of tickets, forcing Leanne to buy more and he secretly phones Nick and Leanne admits she loves him. Nick arrives at the coach station, knowing about the baby and persuades Leanne to stay. Simon is thrilled when Leanne and Nick decide to move in together and when Nick says he is the father of Leanne's baby. Simon is upset when Peter fails to come and watch Simon collect an award, but is pleased when he returns. Simon witnesses Peter kissing his step-aunt, Toyah Battersby (Georgia Taylor), with his new drone. Peter leaves cigarettes at Leanne's flat and Toyah attempts to take the blame, but Simon is forced to cover for her. Simon confides in Eva about Peter and Toyah's relationship. When Leanne finds out about Toyah and Peter, and that Eva knew, she disowns them and when they attempt to apologise, Simon warns them Leanne's blood pressure is too high. Peter allows Simon to go to a party, but his family struggle to get hold of him and he is returned home by the police after the group split and his phone died.
The character of Simon was re-introduced in late 2008 when his on-screen father Peter (Chris Gascoyne) also returned to the soap. Peter had been given custody of his son after his mother Lucy (Katy Carmichael) was diagnosed with terminal cancer. Both characters' returns saw them slowly develop a father-son relationship.
In March 2015, it was announced that the character of Simon would be involved in a domestic abuse, with it being where Simon is the perpetrator and his mother Leanne would be the victim. Executive producer Kieran Roberts said "It’s a really interesting story. It’s come from character, as Simon is a child who has obviously been through a very difficult few years with the death of his mother, his dad’s alcoholism and then being passed around by the adults in his life. He’s seen a lot of difficult things and he’s got some more difficult things to go through this year in the next few months. I can’t give much away, but there is at least one other major trauma that Simon is going to have to go through. I think it’s fair to say that he’s going to come through all of this a little bit damaged. We’re going to explore how that impacts on his relationship with Leanne, and we’re going to touch on this issue of domestic violence from a child against a parent."
Jane Danson, who plays Leanne Tilsley, said of the storyline in September 2015 that she had doubts when she heard about the domestic abuse plot "It's quite interesting. When they proposed this storyline, I was a bit concerned because I thought historically, as we've seen, Leanne's quite a strong character. I thought, 'She wouldn't take that from a child!' But the way it's been done is quite clever. He's a child who's been through so much with his dad, with the alcoholism, and he's lost so many people in his life. She's been the one constant, so she'll never give up on him. It's been really great to play out, because they've pretty much done it in real time. It's not just been two weeks of a storyline, they've played it out and we continue to play it out with what we're filming at the moment. It's been quite interesting to see a different side of Leanne as well."
In November 2015, it was announced that Simon would lash out at Amy at Christmas as part of the domestic abuse plot. A source said that "The Barlows are going to be central to Coronation Street in the run up to Christmas. The close-knit family will be put under extreme strain and viewers will be left wondering if they can get through the turmoil."
An article discussing young child actors published to The Guardian claimed that Bain's performance as a child actor in the role of Simon "seems to be the nation's favourite". It also described the character as "undeniably cute" and "wise beyond his years", with "great onscreen chemistry with his dad". The author opined that his father Peter's breakup with Leanne would have been "much more tedious" without Simon's performance. The same article pointed out that Simon "has learned to be resourceful...he has survived a fire, a kidnapping, and has gone missing in Blackpool – from where he managed to make his way back to Weatherfield." It also stated that when Simon "joined forces" with Joshua Peacock, they made "a formidable team."
When the character of Simon ran away whilst in Blackpool and later returned on his own to his father Peter's doorstep, he said "Ah've been on two trains and a bendy bus...Nightmare. Don't suppose there's any chocolate milk going?". An article published to The Independent opined that it was "a line that sums up the sweet-and-sour storylines that have kept Coronation Street going for nigh on half a century: 50 years of chocolate milk and nightmares".
Bain won the "Best Young Performance" award in the British Soap Awards 2011 for his portrayal of Simon.