Erba (previously Erba-Incino, as it was formed by the union of these two places, together with some smaller districts) is a comune (municipality) of some 16,000 inhabitants in the Province of Como in the Italian region Lombardy. It is located north of Milan and about east of Como in the traditional region of Brianza at the foot of the Lombard Prealps and close to Monte Bollettone.
It received the honorary title of city with a presidential decree on May 12, 1970. Erba borders the following municipalities: Albavilla, Caslino d'Erba, Castelmarte, Eupilio, Faggeto Lario, Longone al Segrino, Merone, Monguzzo, Ponte Lambro, Proserpio.
Erba was the site of the murder of four people including a 2-year old baby in December 2006, an event known as the . A married couple, the victims' neighbors, were arrested for the murders.