Sisse Marie Welling (born 25 February 1986) is a Danish politician of the Green Left. Welling took office as lord mayor of Copenhagen on 1 January 2026, the first non-Social Democrat to serve in the role. She has served as mayor for health and care since 2017.
Welling grew up in Aarhus, and completed her upper secondary education at Aarhus Statsgymnasium in 2005. She lives on Amager with her husband, and their two children.