Sozzini, Sozini, Socini or Socin is an Italian noble family originally from Siena in Tuscany, where the family were noted as bankers and merchants, jurists and humanist scholars. The family has been described as "the most famous legal dynasty of the Italian Renaissance." A noble family from Bellinzona that later settled in Basel is believed to be descended from the family from Siena; this family became part of the Basel patriciate from the 16th century.