The husband of children's author Mem Fox has been given a suspended jail sentence for his affair with a troubled drama student.

Malcolm Arthur Fox, 66, was convicted in the South Australian District Court last month on four counts of unlawful sexual intercourse in 1984 with the then 17-year-old boy.

Prosecutor Tim Preston told Fox's trial the former teacher had oral sex with the teenager after the boy turned to him for help after being sexually abused.

Fox denied this and has lodged an appeal.

During sentencing submissions Fox was praised for his career, and by former students for his mentoring and support.