Monica Nielsen (born 20 July 1974) is a Norwegian politician and deputy member of the Storting. A member of the Labour Party, she has represented Finnmark since October 2025.
Nielsen was born on 20 July 1974. She grew up in Alta and studied economics and administration at Finnmark University College.
Nielsen was mayor of Alta from 2015 to 2025. She was the Labour Party's third placed candidate in Finnmark at the 2025 parliamentary election but the party won only two seats in the constituency. She became the party's first deputy representative () in the constituency. She entered the Storting on 1 October 2025 as a permanent substitute for Minister of Fisheries and Ocean Policy Marianne Sivertsen Næss.