Alfonso, also called Anfuso or Anfusus (c. 1120 – 10 October 1144), was the Prince of Capua from 1135 and Duke of Naples from 1139. He was an Italian-born Norman of the noble Hauteville family. After 1130, when his father Roger became King of Sicily, he was the third in line to the throne; second in line after the death of an older brother in 1138. He was the first Hauteville prince of Capua after his father conquered the principality from the rival Norman Drengot family. He was also the first Norman duke of Naples after the duchy fell vacant on the death of the last Greek duke. He also expanded his family's power northwards, claiming lands also claimed by the Papacy, although he was technically a vassal of the Pope for his principality of Capua.