Guðmundur Ingi Guðbrandsson is a former member of the Icelandic Parliament. He served as Minister of Social Affairs and the Labour Market, and concurrently as Minister for Nordic Co-operation, from 28 November 2021 to 17 October 2024. He was Minister for the Environment and Natural Resources from 30 November 2017 to 28 November 2021. He represents the Left-Green Movement and is currently the vice-chair of the party. Previously, he served as chair from April to October 2024 and as vice-chair from October 2019 to April 2024. He has also been the CEO of Landvernd, the largest nature conservation and environmental NGO in Iceland, from 2011 to 2017.

Guðmundur holds a BSc degree in biology from the University of Iceland and a master's degree in environmental science from Yale University. He has worked with research in ecology and environmental studies at the University of Iceland and at The Soil Conservation Service of Iceland. He then worked at The Institute of Freshwater Fisheries in Hólar in Hjaltadalur. Between 2006 and 2017 he was a part-time teacher at the University of Iceland, the Agricultural University of Iceland and the University Center of the Westfjords. He has also worked as a ranger in Þingvellir National Park and Vatnajökull National Park.

He was one of the founders of The Icelandic Association of Environmentalists and was the first chairman from 2007 to 2010, and also served on the board of The Society for Former Fulbright Grantees in Iceland, from 2013 to 2017, and as a chairman for the last year.