Cosgrave is a surname. Notable people with the surname include:
Fran Cosgrave (born 1977), Irish nightclub ownerJames Cosgrave (died 1936), Irish nationalist politicianJohn B. Cosgrave (born 1946), head of the mathematics department of St. Patrick's CollegeLawrence Moore Cosgrave (1890–1971), Canadian signatory to the Japanese Instrument of Surrender at the end of World War IILiam Cosgrave (born 1920), fifth Taoiseach of IrelandLiam T. Cosgrave (born 1956), former Fine Gael politician in the Republic of IrelandMichael Joe Cosgrave (born 1938), Irish Fine Gael politicianNiamh Cosgrave (born 1964), former Fine Gael party politician from Dublin, IrelandPhilip Cosgrave (died 1923), Irish Cumann na nGaedhael party politicianW. T. Cosgrave (1880–1965), Irish politicianLiam Cosgrave (born 2000), Ophir Rugby Player