Fennell is a surname. Notable people with the surname include:
Alan Fennell (1936–2001), British writer and editor
Albert Fennell (1920–1988), British film and television producer
Dale Fennell (born 1957), English rugby player, son of Jack
Dave Fennell (born 1953), Canadian football player
Desmond Fennell (1929–2021), Irish writer, philosopher, and linguist
Eamonn Fennell (born 1984), Gaelic football player
Emerald Fennell (born 1985), English actress, filmmaker, and writer
Frederick Fennell (1914–2004), American music conductor
Hernán Fennell (born 1988), Argentine cricketer
Jack Fennell (1933–2019), English rugby player, father of Dale
Jan Fennell, dog trainer and writer
Jane Fennell, Australian TV presenter
John Fennell, Canadian luger
John Lister Illingworth Fennell, British historian of Russia
Joseph Fennell (1835–1919), Anglican priest
Kevin Fennell, American drummer, Guided by Voices
L. Raymond Fennell (1893–1986), Canadian politician
Marc Fennell (born 1985), Australian film critic, technology journalist, radio personality and author Nuala Fennell (1935–2009), Irish economist and politician Patricia Fennell, American writer and businessperson Robert Fennell (born 1956), American politician and restaurateur Susan Fennell (born 1953), Canadian politician, mayor of Brampton, Ontario Thomas Fennell (disambiguation) Willie Fennell (1920–1992), Australian actor and comedian