Macedonia ( , Greek: Μακεδονία, Makedonia), is a geographical and historical region of Greece in southeastern Europe. Macedonia is the largest and second most populous Greek region. Together with the regions of Thessaly and Thrace, it is often referred to unofficially as northern Greece. It is located at coordinates .

Its territory covers most of the region of ancient Macedonia, including the birthplace of Alexander the Great. Its name was later imparted to a wider Balkan region that became known in modern times as Macedonia of which it forms 52.4% of the land and 52.9% of the population. It was part of the Ottoman Empire until 1912. In 1913, most of the Ottoman lands in Europe (including Macedonia) were divided between the surrounding countries of Greece, Serbia, Bulgaria, Albania and Montenegro. The new borders between Greece and the Ottoman Empire were reconfirmed in the Treaty of Athens, in 1913.