Stephanie Scully (also Hoyland) is a fictional character from the Australian soap opera Neighbours, played by Carla Bonner. She made her first screen appearance during the episode that was broadcast on 20 October 1999. Following Bonner's decision to quit the show after eleven years, Steph departed on 24 November 2010. In November 2012, it was announced that Bonner would be reprising the role for a two-month guest stint and Steph returned on 15 April 2013. Bonner reprised the role permanently in July 2015 and made her on-screen return on 2 October 2015. On 17 May 2018, it was confirmed that Bonner would be departing the show imminently and Steph made her final appearance on 7 June 2018. Bonner made a cameo in the show's final episode broadcast on 28 July 2022.

Steph is the eldest daughter of Joe (Shane Connor) and Lyn Scully (Janet Andrewartha). Steph's storylines have included marrying Max Hoyland (Stephen Lovatt), becoming a stepmother to his children Boyd (Kyal Marsh) and Summer (Marisa Siketa), battling breast cancer, pregnancy, being the victim of a stabbing and infidelity. Upon her return, Steph revealed that she had suffered a breakdown in prison and became determined to win back her former boyfriend, Lucas Fitzgerald (Scott Major). After kidnapping Lucas's son, Steph was sectioned. Following her release, she returned to Erinsborough to rebuild her life and reconnect with her son. Steph has proven popular with critics and viewers, who named her their favourite Neighbours character in 2010.

The Scully family were created and introduced to Neighbours following the departure of Martin family. Stephanie was introduced along with her parents Lyn (Janet Andrewartha) and Joe (Shane Connor) and her younger sisters Felicity (Holly Valance) and Michelle (Kate Keltie). Reporters for eBroadcast said Stephanie was twenty years old and preferred leathers and motorbikes to the hobbies of her peers. In September 1999, Jason Herbison of Inside Soap reported that former Heartbreak High star Emma Roche had joined the cast of Neighbours as Stephanie. However, Roche unexpectedly quit the role after three weeks.

When Carla Bonner dropped by to see her agent, she was on the phone to the Neighbours casting director, Jan Russ. Russ asked to see Bonner straightaway for an audition for the part of Stephanie. Bonner had little acting experience, having appeared in television bit parts, but she went over to Russ' office and was given a script for a cold read. She was asked to go to the studio the next day, where she auditioned again. She then received a call to say she had got the part. Bonner had to learn nineteen scenes by the next day and develop the character of Stephanie quickly. Four days after her audition with Russ, she began filming. Bonner had to shoot three weeks worth of scenes in one week.

Steph is the only original member of the Scully family to have remained on the street. Steph is a tomboy with a passion for mechanics and motorbikes. Holy Soap said Steph is "one of the most dependable characters on the street." TV Week describe Steph as being "more into Grand Prix racing than girly stuff, but that hasn't stopped her from having her fair share of weddings and more than her fair share of romantic dramas". They also add that she has proven to be a loyal friend, a great mother to Charlie and a great stepmother.

Steph's later relationships with Max Hoyland (Stephen Lovatt) and Toadfish Rebecchi (Ryan Moloney) were main focal points in her storylining. Steph is strong, but the breakdown of her marriage nearly destroyed her. Of Max's departure and the effect it has on Steph, Bonner stated during an interview with television magazine What's on TV: "Torn. She still loves him but she's also angry with him. I think she wants to move on because she knows she has to prepare herself for the fact he might never come home." Steph's best friend Toadie gives her a shoulder to cry on, they later start a relationship. Bonner further discusses their relationship in the same interview adding: "Steph and Toadie have been friends for years, but it’s never extended beyond friendship. Until now [...] I think it's inevitable when you start spending so much time with someone that after a while they just fit into your life. Toadie’s been a fantastic support to Steph, there every step of the way."

Describing the developments in Steph and Toadie's relationship during 2008, Dan Bennet speaking for Network Ten states: "Steph has already agreed to a long engagement with Toadie, but she's not ready to marry. This relationship will reach a massive fork in the road early in the new year. Toadie will force Steph to decide what she wants from this relationship."

One of the biggest storylines for Steph saw her being diagnosed with breast cancer. Bonner wanted to play the scenes with honesty and said that "it was important that Steph went through the whole thing". Bonner prepared for the storyline by researching the condition. She said "It wasn't something I was going to take lightly it was something very serious. It was important to raise awareness and important not to offend anybody". Bonner also turned to a family friend who had survived breast cancer and asked her questions about the condition. However, with other aspects of the condition, like hair loss, Bonner had to find her "own truth". The storyline was exhausting for Bonner, but it gave her a chance to show a different side to her character and it became a "rewarding personal challenge". On Steph's reaction to the cancer, Bonner said "It's just a huge learning curve and it's a huge life experience".