Ermengard of Italy, also Ermengarda, Ermengarde, or Irmingard (843-896) was a queen and regent of Provence. She was the only surviving daughter of Louis II, Holy Roman Emperor.
Born in 843, in the reign of her grandfather Lothair I, the year that her grandfather and great-uncles partitioned the empire of their own father, she grew up relatively privileged. Her father, Louis II was the eldest son and co-emperor of Lothair I. In 855, when she was 12, Emperor Lothair I died at the age of 60, and her father became Holy Roman Emperor. In 876 aged 33, she married Boso, a Frankish nobleman of the Bosonid family who was related to the Carolingian dynasty and who rose to become King of Lower Burgundy and Provence in 879.
In May 878, she and her husband sheltered Pope John VIII, who was taking refuge from the Saracens, in Arles. After her husband's coup d'état in October 879, she helped defend his cities from her Carolingian relatives. In 880, she successfully defended Vienne itself, the capital, from the combined forces of Charles the Fat and the co-ruling kings of France, Louis III and Carloman. In August 881, the newly crowned Emperor Charles the Fat pillaged and burned Vienne, forcing Ermengard and her children to take refuge in Autun with her brother-in-law Richard, Duke of Burgundy. Meanwhile, Boso fled into Provence.
On Boso's death in January 887, the Provençal barons elected Ermengard to act as his regent, with the support of Richard. In May, Ermengard travelled with her son Louis to the court of Charles the Fat, and received his recognition of the young Louis as king. Charles adopted Louis as his son and put both mother and son under his protection. In May 889, she travelled to Charles' successor, Arnulf, to make submission anew.