Clinton Day (March 17, 1847 - January 11, 1916) was a noted architect active on the west coast of the United States. Day was born in Brooklyn, and moved to California when 8 years old. His grandfather, Jeremiah Day, was president of Yale University, and his father, Sherman Day, was Surveyor-General of California and one of the founders of the College of California, predecessor to the University of California, Berkeley. Day graduated from the College of California in 1868, and received his MA from the same institution in 1874. (He later received an honorary LLD from the college in 1910.) In 1875 he married Grace Wakefield from Cambridge, Massachusetts.