Gilsenan is a surname which may originate with followers of Senán mac Geirrcinn. Notable people with the surname include:
Matthew Gilsenan (born 1971), Irish singer Alan Gilsenan (born 1962), Irish writer, filmmaker, and theater director Conor Gilsenan (born 1992), Irish rugby union player Matt Gilsenan (1915–2013), Irish Gaelic footballer Zak Gilsenan (born 2003), Irish soccer player Michael Gilsenan, Professor Emeritus of Middle Eastern and Islamic Studies and Anthropology