Magnus Magnusson, KBE, was an Icelandic television presenter, journalist, translator and writer. He was born in Iceland but lived in Scotland for almost all of his life, although he never took British citizenship. He came to prominence as a BBC television journalist, and was best known as the presenter of the BBC television quiz programme Mastermind, which he hosted for 25 years.

Under Icelandic naming conventions, his name would have been Magnús Sigursteinsson (Magnús, son of Sigursteinn), but his family adopted British naming conventions and he took his father's surname. Although born in Reykjavík, Magnusson grew up in Edinburgh, where his father, Sigursteinn Magnússon, was the Icelandic consul.