Ulla Isaksson (22 June 1916 – 24 April 2000) was a Swedish author and screenplay writer. She was born and died in , Sweden. In addition to her short stories and novels, Isaksson also wrote scripts for films and plays.
Isaksson was born in Stockholm in 1916, the daughter of Knut Lundberg and Greta Brasch, who was a member of the Immanuelkyrkan church; this gave Isaksson's upbringing a strong religious character, something that marked her early novels. Isaksson graduated from high school in 1937, when she began studying philosophy in 1937. The next year she married David Isaksson. She was awarded the honorary degree of Doctor of philosophy in 1978.
In 1940 Isaksson debuted with the novel Trädet and in 1952 she got her public breakthrough with the novel Kvinnohuset, which was made into a film by Erik Faustman. The first film adaptation of Isaksson's work was Kvinnohuset (1952). Ingmar Bergman adapted her novel Det vänliga, värdiga (1954) in 1958, and after that he hired Isaksson to write the screenplay for the film Jungfrukällan (1960). Her novel Klänningen was adapted by Vilgot Sailor in 1964, Paradistorg became a movie in 1977, directed by Gunnel Lindblom, and Bergman made a television movie of the novel De två saliga (1962).
Several of Isaksson's novels of the 1950s are marked by religious problems, as ultimately in Havet and Dit du icke vill, where 17th century witchcraft trials in a village in Dalarna are portrayed of the bases of contemporary protocols. In her previous books she had written primarily about religious tensions and conflicts. In later novels she also directed analysis against erotic motifs, world problems, women's issues, and parenting.
Isaksson remained married to David Isaksson until 1963, when she married secondly the author Erik Hjalmar Linder. Together with Linder, she wrote a two-part biography of the author and journalist Elin Wagner called Elin Wagner, amazon with two breasts, 1882-1922 (Bonnier, 1977) and Elin Wagner, daughter of Mother Earth, 1922-1949 (Bonnier, 1980).