Ulf Lennart Nilsson (18 September 1948 – 22 September 2021) was a Swedish writer who published more than 100 books and picture books, geared mainly to children and adolescents. He was also the longtime president of the Swedish Academy for Children's Books. A number of his works have been translated into English by Gecko Press. Nilsson died on 22 September 2021, at the age of 73.