Pennefather is a surname. Notable people with the surname include:
David Pennefather CB OBE (born 1945), former Royal Marines officer, became Commandant General Royal MarinesEdward Pennefather PC, KC (1775–1847), Irish judgeJoan Pennefather, Canadian film and cultural executiveJohn Lysaght Pennefather GCB (1798–1872), British soldier who won two very remarkable victoriesSir John Pennefather, 1st Baronet JP (1856–1933), British cotton merchant and Conservative politicianOwen Edward Pennefather Lloyd VC KCB (1854–1941), Irish recipient of the Victoria CrossRichard Pennefather, the 9th Attorney-General of Western AustraliaRichard Pennefather (judge) (1773–1859), Irish judge, praised for his conduct of the Doneraile Conspiracy Trials of 1829Rupert Pennefather, principal dancer in the Royal Ballet Company