Rob Hollins is a fictional character from the BBC soap opera Doctors, portrayed by Chris Walker. Rob was introduced as a police sergeant at Letherbridge police station and made his first appearance during the episode broadcast on 24 July 2009. Rob is the husband of Karen Hollins (Jan Pearson), a receptionist at the fictional Mill Health Centre, as well as the father of Imogen (Charlie Clemmow) and Jack Hollins (Nicolas Woodman). Rob is depicted as a dependable family man and it has been noted that whenever another character needs advice, Rob would always be there to help. Rob's storyline in the programme has included disagreeing with Karen on aborting their baby, accidentally causing his wife's amnesia, suffering from post-traumatic stress disorder (PTSD), becoming a foster parent, being accused of police brutality, and the breakdown and reconciliation of his marriage. Rob's PTSD was explored over the duration of a year with the climax coinciding with Mental Health Awareness Week in 2018, with the storyline being revisited in 2021.

Walker enjoys working with Pearson to portray Rob and Karen's marriage on Doctors and they have stated that despite their numerous breakdowns and reconciliations, the pair will always be strong as a couple. Walker himself devised a storyline for Karen's memory loss which was played out for a year-long story arc; the story involved the couple having a break from each other which they enjoyed since it was something different for them to film. Walker and Pearson won the 2010 British Soap Award for Best On-Screen Partnership, as well as being nominated again in 2022, and winning again in 2023. For his portrayal of Rob, Walker has been nominated for Best Actor, Best Leading Performer, and Best Male Dramatic Performance at the British Soap Awards, as well as receiving nominations in the Serial Drama Performance category at the National Television Awards, Acting Performance of the Year at the RTS Midlands Awards and Best Daytime Star at the Inside Soap Awards.

On his BBC character profile, Rob is described as a "stable and reliable" family man, as well as an alpha male. The profile noted that at work, Rob is highly respected due to his experience as a "seasoned copper". It also explained that he is not the type of person to be intimidated by people in charge and that "if he smells injustice", he will ignore orders to do the right thing, even if it does not work in his favour. On his relationship with Karen (Jan Pearson), the profile noted that they have a "teasing banter" and that Rob can always find a way to make Karen laugh out of one of her dramas. In 2021, Walker talked about Rob's clothing on the soap. He explained that after 12 years on Doctors, he still enjoys wearing the police uniform, but that if he could, he would "definitely tell Rob to buy better clothes". He said that his character needs to chill out and that Rob acts "so middle-aged", joking that he would not "chew the fat with him in the corner of a pub". He added that Rob is "a dependable character", and that when somebody needs advice or support, there is no doubt that Rob would be the ideal person to ask.

When Karen becomes pregnant, she does not want to have the baby, whereas Rob wants a child. She informs him that she wants to have an abortion, which he disagrees with. She has the termination, and as a result, their relationship is strained. She goes to live with her father but eventually tells Rob her plans to reconcile their marriage, and after saving her from a burning building, they recommence their relationship. After Rob accidentally hits Karen with his car, she develops amnesia. She forgets who Rob and her children are and believes that she is 18. After she has recovered her memories and their children move out to attend higher education, Rob and Karen decide to become foster parents.

Bren Lee (Andrea Gordon), the mother of Karen's colleague Ayesha (Laura Rollins), is brought into custody at the police station. Rob's colleague Emma Reid (Dido Miles) is shocked to find that Bren has died in police custody. Rob, the sergeant on shift at the time, had a blackout when he was due to be checking over Bren, and he confides in Emma that he feels responsible. Emma lies to the investigating officer, stating that Rob performed all of the checks diligently. Rob later confesses and Emma is almost suspended. Ayesha struggles to forgive both Rob and Emma, due to feeling that the pair are trying to cover up a case of police brutality. Feeling responsible for Bren's death, Rob stops going to work and has heightened anger levels. He later approaches Ayesha, where he apologises. Due to feeling incapable of being a foster parent, Rob meets with social worker Jane Fairweather (Patricia Potter) and lies to her by saying that Karen is unable to foster due to her history of amnesia. Jane informs Karen of this, who is angry with Rob due to feeling responsible for his state. When the pair foster Jayden Hunt (Ciaran Stow), a 14-year-old with epilepsy, they look into getting him medical aid for his seizures. They discover that Jayden has been using Karen's money to buy marijuana since it eases his condition. Rob warns him not to do it again due to his police career being put at stake, but Karen disagrees. She meets with Iris Nicholson (Jenny Stokes), a local drug dealer, to buy Jayden marijuana. She is stopped by Rob's colleague, Pat Dyson (Dawn Butler), who states that she will not tell Rob. However, Karen later confesses what she has done to Rob, who is angry with her decision to go behind his back.

Due to unexpectedly experiencing post-traumatic stress disorder (PTSD) from a brutal accident he witnessed years prior, he pushes Karen away and forms a close bond with colleague Harriet Shelton (Carley Stenson). When Harriet and Rob are chasing criminals Aaron Jeffries (Zak Douglas) and Lenny Calhoun (Nicholas Chambers), Harriet finds Rob standing over the body of Aaron, who is lying lifeless at the bottom of a staircase. She questions a clueless Rob on what happened and rushes to help Aaron, but Rob cannot remember due to suffering from a blackout at the time. Despite being responsible for pushing Aaron down the stairs, Harriet allows Rob to be framed for the attack leading to him being forced into a break from work, which worsens his mental state and his marriage. He eventually learns that Harriet framed him and cuts all contact with her, vowing to improve himself and his marriage to Karen.

Walker and Pearson spoke to Digital Spy about their onscreen chemistry. Talking about their first scenes together, Walker said: "First day on set, in fact, the first scene it was, 'Hi I'm Chris', 'Hi I'm Jan', right get into bed. So that broke the ice." When asked why they work so well together on the soap, he explained: "I think that we're not precious with our own stuff and we always want to give and help each other and that's nice, and we do row very well."

After Karen becomes involved in a memory loss storyline, Pearson reveals that Walker had devised the idea. Walker had wanted an ex of Karen's to run her over and cause the memory loss, but producers decided that Rob would be responsible for the accident. The storyline was a long-running arc, with Pearson telling Digital Spy: "The story has been hugely long and it's still going on. I've been filming it for a year now." Pearson was "utterly delighted" that Rob would be responsible for hitting Karen with his car and joked that Walker was responsible for running her over. She added: "We always knew that Karen and Rob were going to get back together in the end, but the break-up made a nice change from what we normally do. Because it was Chris's storyline and his idea, I really wanted to give it my best shot. What Chris came up with was very detailed - it was extraordinary. If the acting career doesn't work out for him, I think he's got a really good shot as a storyline".