Isabella Colonna (1513 – 1570) was an Italian noblewoman, a member of the Colonna family.
She was the only daughter of Vespasiano Colonna, duke of Traetto (modern Minturno) and count of Fondi, and Beatrice Appiani: However, she grew up with Giulia Gonzaga, Vespasiano's second wife.
In 1531 she married Louis Gonzaga (Rodomonte), an imperial captain of Charles V: the two had a son, Vespasiano I Gonzaga, future Duke of Sabbioneta. One year later Louis died, and Isabella Colonna moved with his parents to Sabbioneta. Later, after quarrels with the latter, she moved to Rivarolo and then, in 1534, to her fiefs in southern Italy.
After she married Filippo Lannoy, prince of Sulmona in 1534, her father-in-law Ludovico Gonzaga opposed, and obtained from the emperor a decree which entrusted Vespasiano's education to his aunt Giulia Gonzaga.
She had 5 children with Philip de Lannoy :
Isabella Colonna died at Naples in 1570; her eldest son Vespasiano inherited all her possessions.