List of Neighbours characters introduced in 2003

The following is a list of characters that first appeared in the Network Ten soap opera Neighbours in 2003, by order of first appearance. Ric Pellizzeri took over the role of executive producer from Stanley Walsh, who left the show in November 2002. The 19th season of Neighbours began airing on 20 January 2003 and Pellizzeri's name was added to the credits on 12 May. That same month saw Rhiannon Fish join the cast as Lisa Jeffries. Talent manager Melody Jones arrived in June and Charlie Cassidy followed in July. Oscar Scully, the fifth child of the established Lyn and Joe, was born in August. September saw three introductions; Izzy Hoyland, Detective Alec Skinner and Rocco Cammeniti. Two new members of the Bishop family arrived in October, Liljana and her daughter, Serena. Wendy Stapleton joined the cast as Nina Tucker's mother, Trixie, and Natalie Blair debuted as Carmella Cammeniti. December saw the introduction of Simon Mallory as Chris Cousens.

Lisa Jeffries, played by Rhiannon Fish, made her first on-screen appearance on 13 May 2003. Lisa was Summer Hoyland's (Marisa Siketa) best friend. Lisa was Fish's first screen role and she joined the cast when she was eleven years old. Lisa was initially supposed to be Australian, but after Fish was cast, the writers made her Canadian. Fish said that she loved playing Lisa and that she "got to do lots of awesome things." She described her character as being "selfish and mean" and said that she enjoyed Lisa turning into a "total bitch." Fish said that people may feel sorry for Lisa and that some scenes showed that it was her mother that had made her into a horrible girl.

Summer Hoyland makes friends with Lisa at primary school, after they both join the girls' soccer team. They try and persuade Jack Scully (Jay Bunyan) to coach them full-time, but he just teaches them some tricks. Jack later decides to take on the role of assistant coach. Lisa joins Summer's family for a trip to the beach and she and Summer go off to look for treasure and the walk onto a nudist beach. Lisa and Summer later join a pony club. When Summer's father, Max (Stephen Lovatt), splits up with Stephanie Scully (Carla Bonner), Lisa begins picking on Summer. She tells her that Max is too old for Steph and the girls fight. Summer tries to apologise, but Lisa tells her that she is no longer invited to her birthday party. During an orientation day at Erinsborough High, Lisa is paired up with Summer's brother, Boyd (Kyal Marsh), who threatens to flush her head down the toilet if she continues to bully Summer. Lisa then reports him to Susan Kennedy (Jackie Woodburne).

At their next soccer game, Lisa and Summer make up when Summer passes the ball to Lisa and she scores the winning goal. Lisa notices that Max is sad and she tells Summer that it was the same with her mother, when her father left her. Lisa and Summer then decide to get their parents together, so they can be sisters. However, Max and Lisa's mother, Andrea (Gail Beker), have nothing in common. When the girls start at Erinsborough High, they are laughed at for having their socks rolled up and they struggle with the large building. Lisa passes a note around her class about Susan's divorce and even after she is caught, she continues writing more nasty notes. Summer refuses to laugh at the jokes. Summer meets a new boyfriend, Caleb Wilson (Joss Kasper), who gives her expensive gifts. Lisa does not believe that Caleb exists, but she is shocked when he turns up at school to meet Summer for lunch. Lisa is then humiliated when she tries to flirt with Caleb and he rejects her. Lisa begins hanging around with her boyfriend and she encourages Summer to smoke. Summer refuses and Lisa calls her a loser, ending their friendship. Summer starts hanging around with Penny Weinberg (Sally Kingsford) and Lisa steals Penny's diary and reads it out to everyone.

Melody Jones, played by Robyn Arthur, made her first on-screen appearance on 13 June 2003.

Melody is a talent manager whose clients included Robbie D (Khi Robertson) and a boy-band called Roger. Melody approaches Nina Tucker (Delta Goodrem) and asks her to sign with her after seeing her perform at Lou's Place. Nina contacts Melody to arrange a meeting and Melody tells her that she does not need her parents to be involved if she wants to sign up. Melody convinces Lou Carpenter (Tom Oliver) to give Nina a regular singing gig at the pub, so she can showcase her music. Nina agree to sign up, but she has to forge her mother's signature on the forms to keep her out of her work. Melody makes attempts to get Nina into the world of showbiz and she arranges for Nina to go to a movie premiere with Robbie D. Nina tries to pull out because she is dating Jack Scully (Jay Bunyan), but Melody tells her that it could be her big break and she goes. Robbie kisses Nina at the premiere and the moment is captured by a photographer. Melody points out that Nina's profile has been raised and she is taking bookings for interviews and gigs.

After a few months, Melody tells Nina that she has a place on an Asian tour for her with Robbie D. Nina agrees to go, but cannot take Jack with her. Weeks later, Nina is shocked to hear Robbie D singing one of her songs on the radio. She contacts Melody who explains to her that she signed a contract which handed over all of her recording rights. Nina owns up to her mother, Trixie (Wendy Stapleton). Lou points out that the contract is not valid as Nina forged a signature on it.

The following year, Stephanie Scully (Carla Bonner) is looking for a wedding dress and she finds Melody working in a bridal shop. Susan Kennedy (Jackie Woodburne) is surprised and makes a dig about Nina. Melody explains that she had given up managing people because she could not trust anyone. Steph leaves the shop after seeing the prices of the dresses. Melody reinvents herself again as a publisher. Janelle Timmins (Nell Feeney) writes a novel and it gets emailed around the town as part of a joke. Melody sees it and contacts Janelle about publishing the book. Melody meets up with Janelle and tells her that it would need to be longer before it can be published. Only the Timmins family knew that Bree (Sianoa Smit-McPhee) had actually written most of the book. A couple of years later, Melody is back working as a sales assistant in a dress shop. Bridget Parker (Eloise Mignon) and Rachel Kinski (Caitlin Stasey) come in looking for dresses for their school formal. Melody believes that they are going to try everything on without buying anything and the girls leave. Bridget tells her mother and aunt what happened and they take Bridget and Rachel back to the shop. They make several purchases with the help of another assistant who gets the commission instead of Melody.