Agnes de Poitou or Empress Agnes (1020-1077) was regent of the Holy Roman Empire from 1056 to 1068.
She was born to William V, Duke of Aquitaine and Count of Poitou and his wife Agnes of Burgundy .
Agnes was the second wife of Henry III, Holy Roman Emperor. Among their children were Judith of Swabia and Henry IV, Holy Roman Emperor.
She was regent during the minority of Henry IV.