Katherine Mallen Kupferer (born November 23, 2007) is an American actress.
Katherine Mallen Kupferer was born in Chicago, Illinois, to Keith Kupferer, an American actor, and Tara Mallen, an American actress.
She began acting at the age of five, during a Chicago Shakespeare Theater's production of Gypsy. In 2018, Kupferer starred in Widows, directed by Steve McQueen.
In 2023, she starred in Are You There God? It's Me, Margaret., and she was cast in Ghostlight, alongside her parents.
In April 2025, it was revealed that she re-teamed with Alex Thompson and Kelly O'Sullivan on the coming-of-age drama film Mouse, which premiered at the 76th Berlin International Film Festival in February 2026.