The House of Obertenghi were a prominent Italian noble family of Longobard origin descended from Viscount Adalbert III, first Margrave of Milan.

The family held the titles of Marquis of Milan and Genoa, Count of Luni, Tortona, Genoa and Milan and regent of the March that took the family's name in the 10th century, the "Marca Obertenga", which encompassed most of the territories of present-day Northwest Italy and parts of Switzerland.

The dynasty is the progenitor of the widely powerful and prestigious House of Este, as well the House of Welf, parent house of the Hanover dynasty.

[3] Other cadet lines include the two of the most ancient Italian noble families, the House of Malaspina and the House of Pallavicini.

[4] Early in 951, Berengar II of Italy finished the reorganisation of the Italian feudal structure begun by his predecessor Hugh.