Siobhan Claire Byrne (born August 13, 1984) is a German-born Irish sabre fencer.

[1] 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.

[2] She also won a bronze medal for her category at the 2007 Junior European Championships in Conegliano, Italy, and was ranked as the no.

[3] Byrne represented Ireland at the 2008 Summer Olympics where she competed in the women's individual sabre event.

She lost the first preliminary round match to Poland's Irena Więckowska, with a score of 8–15.