McCosh is a surname. Notable people with the surname include:
A. J. McCosh (1858–1908), American football player and surgeon Andrew K. McCosh (1880–1967), Scottish industrialist Anne Kutka McCosh (1902–1994), American artist David McCosh (1903–1981), American artist Eric McCosh (born 1938), Hong Kong field hockey player James McCosh (1811–1894), Scottish philosopher John McCosh (1805–1885), Scottish army surgeon and photographer James Eichelburger McCosh (fl. 1870s), builder & operator of McCosh Grist Mill, Randolph County, Alabama Shawn McCosh (born 1969), Canadian ice hockey player Shayne McCosh (born 1974), Canadian ice hockey player Theodore McCosh (1904–1985), American politician from Nebraska