Siv Widerberg (12 June 1931 – 24 December 2020) was a Swedish writer and journalist.

She received an honorary doctorate from the University of Umeå.

She worked as a teacher (1951–1955) and as a journalist (1955–1965) before becoming a freelance writer.

She was a member of the Swedish Academy for Children's Books.

Widerberg died on Christmas Eve 2020.