Hayley Kiyoko Alcroft (born April 3, 1991) is an American singer-songwriter, actress, and author. As a child model and actress, she appeared in a variety of films, including the Scooby-Doo! film series (2009–2010), Lemonade Mouth (2011), Blue Lagoon: The Awakening (2012), Jem and the Holograms (2015), Insidious: Chapter 3 (2015), and XOXO (2016). Alongside her film roles, she also had a recurring role in the TV series The Fosters (2014) and a lead role on CSI: Cyber (2015–2016) and Five Points (2018–2019).

Kiyoko was a founding member of the Stunners in 2007. The group supported Justin Bieber's My World Tour, before disbanding in 2011. After this, Kiyoko issued three solo extended plays: A Belle to Remember (2013), This Side of Paradise (2015), which includes the single "Girls Like Girls", and Citrine (2016). Following the singles "Sleepover", "Feelings", and "Curious", she released her debut studio album Expectations (2018) which reached the top 20 of the charts in the United States, Canada, and Australia. She has since released a fourth extended play I'm Too Sensitive for This Shit (2020) and her second studio album Panorama (2022).

In 2023, Kiyoko released her first novel, Girls Like Girls, which was published by Wednesday Books. The book debuted at number one on the New York Times Best Sellers list for Young Adult Hardcover, and won Goldie Award for Young Adult Fiction by the Golden Crown Literary Society. She has also created a comic book, with the help of Naomi Franquiz and Marla Vazquez, based on her song "Gravel to Tempo".