Siobhan Claire Byrne (born August 13, 1984 in Ostfildern, Baden-Württemberg, Germany) is a German-born Irish sabre fencer. She is a four-time All-American (2005–2008), a three-time Academic All-Big Ten honoree, and a two-time medalist at the Junior World Cup Fencing Series. She also won a bronze medal for her category at the 2007 Junior European Championships in Conegliano, Italy, and was ranked as the no.