Siobhan is the Irish variation of Joan, which is derived from the ancient Anglo-Norman name Jehanne. In this way Siobhan is indirectly related to the name Sinead—the Irish form of Jeannette, which also derived from Jehanne—although Sinead is not a nickname for Siobhan. Siobhan was the name of several early Irish queens and was introduced to the American public by the actress Siobhan McKenna.

While not as popular as the Ariel spelling of Little Mermaid fame, this rendition has achieved popularity in its own right.

Chosen by aviators Charles and Anne Lindbergh for their daughter, Reeve could work as a distinctive alternative to Reese. While it is currently more popular for boys, nine girls received the name in a recent year, meaning around 20% of all Reeves born in the US were girls.