"The Suicide of Kiaros" is a short story written by L. Frank Baum. It was first published in the September 1897 issue of The White Elephant. A slightly-revised version of the story appeared in the November 1954 issue of Ellery Queen's Mystery Magazine. The story was reprinted in The Baum Bugle in 1988, and was anthologized in the collection Murder Takes a Holiday in 1992.

The story, Baum's contribution to the "locked room" mystery, may have been rooted in an incident in Baum's early life, when he was working as a clerk in a dry-goods store: he found the body of a fellow worker, an apparent suicide, locked in a storeroom.

"The Suicide of Kiaros" is one of the author's few ventures into the genre of straight detective and crime fiction. Elements of that genre, however, do occur repeatedly in the juvenile novels he wrote for both male and female audiences through the remainder of his career, notably the popular Aunt Jane's Nieces and Mary Louise series.

Some readers have considered "The Suicide of Kiaros" one of Baum's best short pieces, as well as a rare display of the writer's "dark side." For a lighter example of Baum's crime fiction, see "The Loveridge Burglary."