World Most popular surnames by U.S. State April 13, 2017 Alex This post may contain affiliate links. As an Amazon Associate, we earn from qualifying purchases. Smith is the most common last name in the U.S. Reddit user: nodougbutdoug Related Posts:The Most Common Last Name In Every CountryHow Each State got its NameEvery Country’s Favorite Children’s Toy, from Dolls…Map showing countries which since independence have…The Most Popular Consumer Brands in the World and…Map of common US surnamesMost common surnames in the Italian RegionsWhich language does every country want to learn?