Sydney Park was born on October 31, 1997, in Philadelphia, Pennsylvania. She was born to an African American mother and a Korean American father. Park was the youngest comedian to ever appear at the famed Hollywood Improv (now The Improv) in 2003. Under the stage name Syd, the Kid, she auditioned for the inaugural season of the American reality program America’s Got Talent in 2006 where she made it to the semi-finals. However, Park had to drop out because of her acting career. In 2006, she made her television debut on the teen comedy That’s So Raven. She then was cast as Ellie Danville, Detective Jo Danville’s adopted daughter, on CSI: NY in 2010.
Park also appeared in the independent dark comedy Spork in 2010 as Tootsie Roll. In 2016, she began portraying Cyndie on The Walking Dead. She played Meredith in the ghostly horror flick Wish Upon in 2017 and starred in the YouTube Science Fiction series Lifeline in the same year. In 2019, Park starred in the television series called Pretty Little Liars: The Perfectionists as Caitlin Park-Lewis which aired on Freeform. However, Freeform terminated the series after one season.
Park starred as Winter in the Netflix horror-comedy series Santa Clarita Diet’s third season in 2019. She was cast as the lead in the romantic drama First Love, opposite hero Fiennes Tiffin in May 2021. In October 2021, she starred as Makani Young in the Netflix slasher thriller, There’s Someone Inside Your House.