|Sydney Brower as Arianna Horton|
|Days of our Lives|
|Portrayed by|| Harper & Sydnee Udell (2013-19)|
Sydney Brower (2019-present)
|Current status||Present; Recurring|
|First appearance||May 22, 2013|
|Created by||Gary Tomlin and Christopher Whitesell|
|Introduced by||Ken Corday, Lisa de Cazotte and Greg Meng|
|Fullname||Arianna Grace Horton|
|Namesake(s)|| Arianna Hernandez|
|Born||May 21, 2013|
|Age||10 (SORAS’d in 2019)|
In November 2019 after the time jump, Sydney Brower took over the role of an aged Arianna.
She was named after her deceased aunts, Arianna Hernandez and Grace DiMera, the baby her maternal uncle raised. Grace's father Chad DiMera approved of this. Her godparents are Sonny Kiriakis and Abigail Deveraux.
She is being raised by her mother Gabi as a single mother after her father Will Horton was murdered and is still close to Sonny Kiriakis who is her step-father. Arianna is close with Chad DiMera and Abby Deveraux. In 2017, it's revealed that her father Will is alive and in Memphis.
Arianna is conceived when her parents have a one-night stand in August 2012. When Gabi finds out that she is pregnant she decides on an abortion, but can't go through with it. Gabi is in a relationship with Will's cousin, Nick Fallon, and Nick wants to be Arianna's legal father. Will reveals that he is actually Arianna's father at Nick and Gabi's first attempt at a wedding in January 2013. Will signs away his rights after Nick blackmails him (about him shooting EJ DiMera) in March 2013. Leading up to her birth, Gabi and Nick are held hostage by Jensen, a former prison inmate of Nick's. Sonny and Will arrive and Sonny is able to escape with Gabi; but Will stays to help Nick. Gabi reveals that she has been having small contractions all day and Sonny finds an abandoned shed in which to deliver the baby. Sonny delivers Arianna, and Gabi and Arianna are brought to the hospital, and given a clean bill of health. After she is born, Gabi and Nick sends back her birth certificate before Gabi signs it, to have Will's name stated as "father".
Arianna and her mother move in with Will and Sonny, and they raise Arianna as a three-parent family. In 2014, Sonny marries Arianna's father, Will, becoming her step-father. When Gabi is imprisoned for the murder of Nick, Arianna is raised by her two dads. Arianna is reunited with her mother when she is released from prison in September 2015; but her happiness is cut short when her father Will is apparently murdered, and Sonny, stricken with grief, leaves town, and Gabi is left to raise Arianna on her own. Sonny returns in 2016, and recommences co-parenting her with Gabi. In late 2017, it is revealed that Will is, in fact, alive. He is suffering from amnesia after being strangled and abducted, and has no memory of his life before. As soon as he returns to Salem, Arianna and Gabi come to see him. Despite not remembering them, Will treats Arianna as his daughter, and begins to take part in co-parenting Arianna again. When Will's amnesia leads to Arianna's two dads divorcing, Sonny continues to co-parent her, as does Will.
In 2018, her mother Gabi is wrongfully imprisoned, and Will and Sonny tell Arianna that her mom is working away from home. After Gabi is proved innocent, Will and Sonny tell Ari that her mom is coming home, but Gabi's release is delayed for several more weeks due to a murder at the prison, and when Gabi finally gets out, Arianna, feeling unloved by her mother, is angry and unwelcoming towards her.