Siobhán Kate Cullen (born February 1990) is an Irish actress. She began her career as a child actress, making her debut in Marina Carr's By the Bog of Cats (1998) at the Abbey Theatre. She landed her first major screen role in Eoin Macken's horror film The Inside (2012). Cullen is known for her roles in the RTÉ1 and BBC One miniseries Paula (2017), the web series Origin (2018), the ITV adaptation of The Long Call (2021), and the BritBox series The Dry (2022). She was named a 2022 Screen International Star of Tomorrow.