- For the musician, see Sia (Musician).
Sia is a student at South Park Elementary who first appears in the Season Eighteen episode, "The Cissy". Although no other character refers to her by name in the episode, her voice credit is listed as "Sia".
She has very pale short blonde hair with bangs, and wears a short black jacket over a black-and-white striped shirt, with a red skirt. Her hairstyle (and name) may be a homage to singer Sia, who provides Lorde's singing voice in the same episode.
Sia exhibits frustration and anger at Cartman's refusal to leave the girls' bathroom.
- ""South Park" The Cissy (TV episode 2014)". IMDb.com.