Horace Oscar Axel Engdahl is a Swedish literary historian and critic, and has been a member of the Swedish Academy since 1997. He was the permanent secretary of the Swedish Academy from 1999 to June 2009, when he was succeeded by Swedish author and historian Peter Englund.

The Swedish Academy, founded in 1786 by King Gustav III, is one of the Royal Academies of Sweden. Its 18 members, who are elected for life, comprise the highest Swedish language authority. Outside Scandinavia, it is best known as the body that chooses the laureates for the annual Nobel Prize in Literature, awarded in memory of the donor Alfred Nobel.