Grant arrives in Albert Square with his brother Phil Mitchell, as the owners of the local garage, The Arches. Grant had returned from being a paratrooper in the Army involved in the Falklands War. After a brief fling with Julie Cooper and getting involved in various dodgy deals, Grant starts wooing the local barmaid, Sharon Watts. Sharon is attracted to his machismo, and soon their flirting progresses into a relationship. Fiercely protective of his girlfriend, most of Grant's initial problems in the Square revolve around his over-possessive nature and jealousy. He puts the landlord of The Queen Victoria public house, Eddie Royle, in hospital after he makes a pass at Sharon; he later becomes prime suspect for Royle's murder, but Nick Cotton eventually owns up to the crime. In the wake of this, Grant decides to re-enlist in the army, but is rejected when he fails their psychiatric tests.
Despite his hot-headed tendencies, Sharon sees a different side to Grant, and when he proposes marriage to her, she accepts on the condition that he buys her her childhood home, The Queen Vic, which he does. Grant marries Sharon and together they run The Queen Vic. Their marriage is stormy and punctuated with violent rows and fights. Grant is desperate for a child, and when he discovers Sharon is still taking contraception, he smashes up the pub and then disappears. In his absence, Sharon is comforted by Phil and they begin an affair, although this comes to an abrupt end when Grant returns and promises to change his ways. He cannot live up to his promises however, and on Sharon's birthday, Grant sets fire to The Queen Vic to generate insurance money to pay off debts. He does not check to see if Sharon is out of the way, and she and her dog Roly nearly die in the blaze. The insurance money is insufficient, and Sharon reacts with fury when she discovers what Grant has done. She leaves Grant for a while, and when she returns and attempts to seize control of The Queen Vic; Grant turns violent, assaults Sharon and her best friend Michelle Fowler and is imprisoned on remand. While he is in prison, Sharon and Phil rekindle their affair, but neither can confess to Grant, and it ends when he is released from prison. Sharon and Grant patch up their relationship; however, Grant discovers a tape on which Sharon talks about her affair with Phil, and plays it to a packed pub at Phil and Kathy Beale's engagement party. Grant batters Phil in revenge, leaving him with a ruptured spleen, and bullies Sharon until she flees to the United States. She returns briefly to enact revenge, making Grant realise that he is still in love with her, he chooses to be with Sharon over his family. Sharon is ready to turn him down in front of a packed pub and his family. However, in the end, she cannot go through with it, and stops him from publicly proposing before he humiliates himself. She then confesses to him that she still loves him, before returning to the US, leaving Grant heartbroken.
Michelle has a volatile relationship with Grant but, following Sharon's exit, falls pregnant following a one-night stand with him and then flees to the US without telling Grant that he is to be a father. Grant would not find out that the baby is his until years later. He goes on to wed a pregnant Tiffany Raymond, although it is unclear whether he or Tiffany's ex-partner Tony Hills is the father. When Grant discovers this, he is incensed and throws Tiffany out. He begins a relationship with Lorraine Wicks, until a paternity test reveals that Grant is the father of his baby, Courtney Mitchell. He reunites with Tiffany to be near his daughter, but by this time his marriage has deteriorated. When Tiffany discovers that Grant has had an affair with her mother Louise Raymond, she plans to flee to Spain with Courtney, but Grant traces her and retrieves Courtney. Tiffany attempts to snatch Courtney but is hit by a car driven by Frank Butcher, Grant's stepfather, and dies as the clock struck midnight. Grant tries to move on by dating barmaid Nina Harris for a while but dumps her after her past as a prostitute is uncovered.
Grant and brother Phil plan to cheat some gangsters to pay off a debt by intercepting a drug deal and stealing a large amount of cash. Before doing the job with Phil, Grant punches Steve Owen. However, the job goes awry when Phil finds out that Grant has had sex with his ex-wife Kathy before doing the job. He confronts Grant after the job and Grant admits he did it in revenge for Phil having sex with Sharon. Phil pulls out a gun, and shoots the steering wheel in their getaway car, causing Grant to plunge the car into the River Thames. Phil is rescued but Grant is not found and presumed dead. A week later it is revealed that Grant is alive. He departed with Courtney and the stolen money to Rio de Janeiro.
Grant returns to Walford with Phil to exonerate his younger sister Sam Mitchell (Kim Medcalf) for the murder of Den Watts (Leslie Grantham); she is being framed by the real murderer is Den's wife, Chrissie Watts (Tracy Ann Oberman). Grant manages to put behind him his differences with both Phil and Sharon, forgiving Sharon when she confesses that she aborted his child. Grant and Phil manage to persuade Sharon, Den's daughter, that Chrissie is the real killer. He finds CCTV evidence of Chrissie confessing to her murder of Den. Sociopathic gangster Johnny Allen (Billy Murray) has a grudge against the Mitchell brothers because of their mother Peggy Mitchell (Barbara Windsor) and uses the tape as bait to try to kill them. The brothers eventually beat Johnny at his nightclub office in order to get the tape, Sam is released from prison and Chrissie is imprisoned. Following this, Grant returns to Rio.
He returns with his daughter Courtney Mitchell (now played by Megan Jossa), citing family and financial problems back in Brazil. Phil tricks Grant to help him in his quest against Johnny to revenge the death of Sharon's second husband Dennis Rickman (Nigel Harman). Amidst arguing amongst the Mitchell brothers, Johnny, armed with a shotgun, captures them and orders his henchman Danny Moon (Jake Maskall) to take them to a forest and kill them. They are rescued by Danny's brother Jake Moon (Joel Beckett), who shoots his brother dead at the last second - saving Phil and Grant. Jake secrets the burial of his brother in the woods and Johnny, after his daughter Ruby Allen (Louisa Lytton) implicitly threatened to disown her father for good, turns himself into the police.
Grant flirts with Jane Collins (Laurie Brett), Ian Beale's (Adam Woodyatt) girlfriend; he seduces her after getting a job working for Jake at the newly reopened Scarlet nightclub. Their affair ends when Phil catches them together and Grant then has a one-night stand with 19-year-old Chelsea Fox - to his mother's outrage. Shortly after, his estranged Brazilian wife, Carla (Christianne Oliveira), shows up in Walford. Grant and Carla resume their relationship, but Carla's ex-partner Ray (David Kennedy) soon arrives to retrieve £12,000 that Carla has stolen from him. Carla and Ray resume their affair and plan to fleece Grant for £25,000. Grant learns of Carla's scam; unbeknownst to Carla he chases Ray away and leads Carla to believe he has fallen for her lies. Grant catches her attempting to steal his money and reacts by dumping her in a litter bin, ending their marriage. Grant and Courtney then leave together for Portugal.
In May 2016, Peggy returns to Albert Square following a diagnosis of terminal cancer. She decides to stop her treatment, but Phil tries to change her mind, enlisting the help of Sharon. Sharon then calls Grant in Portugal, leaving a voicemail saying that his family needs him. Grant returns to the square soon after and walks in on Phil and Peggy. He plans to take Peggy with him back to Portugal, only for her to say that her cancer is active. Grant is angry when Peggy reveals that her plan for him and Sam to learn about it was by letters to them after her death by suicide, however Phil and Grant seemingly convince Peggy not to do this. Grant tells Phil he immediately needs the money that he lent him. Knowing he cannot get it, Grant threatens him unless he returns the money. Grant returns to Portugal, and Sharon has to call him about Peggy having killed herself. When Sam returns to Walford for Peggy's funeral, she reveals that Grant is unable to attend the funeral, although Grant secretly attends, laying a flower and watching from a distance.
When Grant's nephew Ben Mitchell (Harry Reid) goes missing and Phil is reluctant to get the police involved, Sharon contacts Grant for help, but Courtney (now played by Alice Nokes) meets Sharon instead; Grant has not seen the messages. Sharon decides to go to the police and finds Grant outside the police station as a result of being drunk and disorderly. Grant goes to The Queen Vic where he flirts with Belinda Peacock (Carli Norris). Grant tells Courtney that Phil killed Peggy. When Courtney tells Grant that Sharon wanted to meet him, he goes to see Sharon and declares his love to her, but she is not interested. Grant accuses Phil of killing Peggy and asks for his money back, but Phil does not have it. Grant tries to persuade Sharon to go to Portugal with him but she declares her love for Phil. Grant telephones Courtney to ask to stay with her but she refuses. Grant then meets Belinda again and they go to her home for sex but are interrupted by her family. Phil finds a letter in Sharon's bag that Michelle sent Peggy, revealing that Grant fathered Michelle's child, Mark Fowler (Ned Porteous) 21 years previously. Grant visits Jane where he learns that she has been paralysed by her adoptive son Bobby Beale (Eliot Carrington). He admits that he has lost his home and business in Portugal and is in debt. Grant and Jane both comfort each other, but Ian walks in on them and shouts at Grant for deserting his family. Grant leaves, ignoring Phil, who is attempting to tell him about Mark. Courtney calls Grant, who is staying with Aunt Sal (Anna Karen) due to losing his villa and bar in Portugal, for help after Ben and Jay Brown (Jamie Borthwick) are kidnapped by the men who attacked Ben and killed his boyfriend Paul Coker (Jonny Labey). Grant rushes to Courtney's aid and assumes Mark is attacking her, but Sharon tells him he is Michelle's son. Phil initially insists he does not need Grant's help but then accepts it. Phil collapses so Grant vows to rescue Ben. Mark gets in Grant's car to help him, and they find Ben and Grant scares off the men. Grant reconciles with Phil, admitting he no longer wants the money Phil borrowed from him, and Phil tells Grant that Mark is his son. Courtney is angry with Grant when he stops her kissing Mark. Grant confronts Ian about keeping the secret for so long and punches him after Ian insults his parenting skills. Sharon tells him the reasons Michelle did not want him involved and Grant agrees that Mark would be better off not knowing, but Jane convinces Grant otherwise, so Grant offers to take Mark for a drink. After a heart to heart, Grant realizes that Mark would be better off not knowing and decides to return to Portugal after seeing Phil. Phil gives him money, and he reunites with Courtney and the pair return to Portugal. Mark also works out who Grant is, but Sharon convinces him he is better off with his adoptive father, Tim.
Behind the Scenes
- For the roles of Phil and Grant Mitchell many actors were screen-tested together. This was done to assure the chosen actors – who would work together – had a strong rapport and physical resemblance. Producer Corinne Hollingworth commented: "There were some good actors we had to turn down because we couldn't find the 'right' brother." Steve McFadden, an actor who had worked extensively in television, was cast as Phil. His shape, skills in stage fighting and a variety of sports including boxing, football and karate made him an ideal choice to play one of Walford's latest "tough-men." Ross Kemp got the role of Grant. Both actors worked well together and shared similar physical characteristics, such as short cropped hair and a "round, open face" – facial characteristics also shared by Daniella Westbrook, who was chosen to play their sister Samantha because of this.
- Actor Ross Kemp had previously played a character in Emmerdale in 1986 and 1987 (then known as Emmerdale Farm). This character was Graham Lodsworth, the illegitimate son of Dolly Skilbeck. Graham Lodsworth was similar to Grant, a bit of a thug who was in the army. This may have played a part in Ross landing the role of Grant Mitchell.
- The Mitchell brothers quickly became two of the soap's most popular characters and storylines involving them began to dominate the programme.
First and last lines
"Guess we'll just have to rob a bank, won't we? (Final line, to Courtney Mitchell)