Petronilla of Lorraine (c. 1082 – 1144) was a daughter of Theodoric II, Duke of Lorraine and Hedwige of Formbach. Through marriage to Floris II, Count of Holland, she became Countess of Holland. After the death of her husband, she acted as regent for her son Dirk VI.
Named after her maternal grandmother, she changed her name from Gertrude to Petronilla. After her husband's early death, she became regent for their son, Dirk VI. After Baldwin VII, Count of Flanders died without heirs, she supported her son's claim to become Count of Flanders, but Baldwin was eventually succeeded by Charles I. In the struggle for power between Dirk and his younger brother Floris the Black, she first supported the latter. At his second attempt, she refused to support him though.
Petronilla founded an abbey in Rijnsburg, where she was buried after her death in 1144.
With Floris II she had the following children: