Napier is an electorate created in 1977 for the South Australian Legislative Assembly in the outer northern suburbs of the Adelaide metropolitan area, including the suburbs of Blakeview, Davoren Park, Elizabeth Downs, Evanston South, Kudla, Munno Para, Smithfield and Smithfield Plains, parts of Craigmore, Evanston Park and Munno Para Downs; as well as semi-rural Bibaringa, One Tree Hill, Sampson Flat, Uleybury and Yattalunga, and part of Humbug Scrub. Napier is named after Sir Mellis Napier, who was Chief Justice of South Australia for 25 years and a total of 43 years in the Supreme Court.