Home and Away is an Australian television soap opera. It was first broadcast on the Seven Network on 17 January 1988. The following is a list of characters that appeared in 2018, by order of first appearance. All characters are introduced by the soap's executive producer, Lucy Addario. The 31st season of Home and Away began airing from 29 January 2018. Dean Thompson and Colby Thorne were introduced during February. April saw the first appearances of Lance Salisbury and Ebony Harding, while Ty Anderson made his debut in May. September saw the arrival of Chelsea Campbell. Dean's mother Karen Thompson was introduced in October. Simone Bedford and Bella Nixon began appearing from November.

Dean Thompson, played by Patrick O'Connor, made his first appearance on 1 February 2018. O'Connor began filming five months prior to his casting announcement on 13 January 2018. He had previously auditioned for other Home and Away characters, and came close to securing the roles, before being cast as Dean. This is O'Connor's first acting role. Of his casting, he stated "Home and Away is obviously known as a launch pad for many actors’ careers. Obviously going into the type of role that this is, being a River Boy and there being a story there already that is so big and well known, it means there is a legacy there to play around with and being a bad boy on the show is exciting." Dean is a member of the show's River Boys group, who were introduced in 2011 with the arrival of the Braxton brothers. Dean was branded "the new bad boy of Summer Bay" by Jonathon Moran of The Daily Telegraph. While O'Connor described him as "cheeky" and said that he loves AFL. The actor added that he likes that his character has tattoos, as he has always wanted one.

Colby Thorne, played by Tim Franklin, made his first appearance on 6 February 2018. Franklin's casting was confirmed in December 2017, after he was photographed filming scenes at Palm Beach, the show's outdoor filming location. He learned from his agent that he had secured the role of Colby on his 27th birthday. He stated, "My agent sang 'Happy Birthday', but changed my name to Colby. When I heard it, I jumped out of my seat and screamed – it was the best gift." Colby is a police constable. Franklin said Colby's "turbulent upbringing" led him to join the force. He also told Tamara Cullen of TV Week, "I believe that any character has to come from a reality within myself. We've both had traumas and heartache in our past – as we all have – so I try to bring as much of myself to the role." Colby is a former member of the River Boys surf gang, and a love interest for Jasmine Delaney (Sam Frost).

Lance Salisbury, played by Angus McLaren, made his first appearance on 17 April 2018. McLaren's casting and character details were announced on 16 April 2018. Of joining the cast, McLaren commented, "It's very exciting. It hit home for me when I walked into the Diner and all the characters I've grown up watching were there." McLaren was reunited with his former Packed to the Rafters co-star James Stewart, who plays Justin Morgan. Lance is a federal agent and best friend of Robbo (Jake Ryan). Lance is involved with the circumstances surrounding Robbo's amnesia and he helps out as the "mystery slowly gets unpacked." Lance also wants his friend to get justice. The character returned the following year.

After Robbo is brought in to an AFP base, Lance helps him to recall his memories and identity. Lance explains that Robbo's real name is Ryan Shaw and that he is a federal agent, whose family were killed when he began investigating corruption in the force. Robbo went undercover as Beckett Reid and he was sent to Summer Bay to protect Kat Chapman (Pia Miller). The federal police were unsure whether Robbo's amnesia was real or not, so they did not intervene. Lance drives Robbo back to Summer Bay and tells him that all the charges against him have been dropped. He also returns all of Robbo's belongings, including his birth certificate, passport, driver's licence and credit cards. Lance advises Robbo to think about returning to the AFP before he leaves. Robbo calls Lance, but he remains reluctant to accept his offer to rejoin. Lance and Robbo team up to investigate a smuggling operation, but Robbo has to retrain and Lance informs him that he needs to pass a psych evaluation. Robbo refuses and Lance suggests that he becomes an instructor instead, but Robbo soon realises that he no longer wants to do police work. Robbo later contacts Lance to ask him to run a background check on Ebony Harding (Cariba Heine).

Lance returns to the Bay for Robbo's pre-wedding dinner at Salt, after being invited by Colby Thorne (Tim Franklin). He meets Robbo's fiancée Jasmine Delaney (Sam Frost) and he and Robbo both notice that something is bothering her. On the day of the wedding, Lance receives a call and later tells Robbo that his parents will not make the ceremony due to car trouble. Lance continues to check his phone and later asks Colby Thorne to identify a guest outside the church. After allowing Robbo and Jasmine to enjoy a moment of their wedding reception, Lance and other AFP officers move in to take the couple into protective custody. They, along with Tori Morgan who is carrying Robbo's child, are taken to a safe house, where Lance explains that the people who killed Robbo's family are back. Robbo and Jasmine decide to return to the Bay, and Lance deputises Robbo back into the AFP. Lance stays with Tori at the safe house, until he decides to go back into the field. He assures her that Scott Larkin (Trent Baines) is trustworthy, and that he will do his best to get her home to her family. Lance is later murdered by Ouroboros Gang as a message to Robbo to stop him from testifying

Ebony Harding (also Easton), played by Cariba Heine, made her first appearance on 19 April 2018. The character and Heine's casting was confirmed during a trailer which aired before the show's break for the 2018 Commonwealth Games. Heine sent a taped audition to the casting directors while she was overseas. Weeks later, she learnt via email that she had secured the role of Ebony. Ebony was introduced as the show's new villain, who wants revenge on some of the residents of Summer Bay. She is connected with the kidnapping of Justin Morgan's (James Stewart) daughter Ava Gilbert (Grace Thomas). Eliza Velk of Yahoo7 Be speculated that Ebony also has a connection to criminal Boyd Easton (Steve Le Marquand) and commented, "Either way something bad is brewing in the bay." Heine later said that she was excited to play a villain, adding "She's pretty despicable, so I hope she gets a rise out of people!"

Ebony goes to Northern Districts Hospital and pretends to be a doctor, after learning her brother Boyd Easton has been brought in. After over hearing that her brother has died, she goes to see her mother, Hazel Easton (Genevieve Lemon) and they both swear revenge on the people who are responsible for Boyd's death. Ebony comes to Summer Bay and begins trying to get to know Colby Thorne (Tim Franklin), the police constable who shot Boyd. She slashes her car tyre, hoping Colby will help her change it, but he has to leave and Hunter King (Scott Lee) helps out. Hazel tells her to hurry up and make everyone pay, but Ebony replies that she wants to have some fun and plans to go after Willow Harris (Sarah Roberts) and Justin Morgan too. Hazel continues to doubt Ebony's plan. Ebony brings her car to Justin's business Summer Bay Auto for a service, and later stages a car crash, hoping to discredit the garage. Ebony threatens to sue Justin for $100,000 for her neck injury and loss of potential earnings. Justin offers her a $30,000 settlement, which she accepts. He also gets her a job at his brother's restaurant, Salt. Ebony breaks into Colby's apartment and learns he has a younger sister. She continues to bond with Colby, before sabotaging his relationship with Jasmine Delaney (Sam Frost).