Which gulf in the Aegean Sea has Thessaloniki on its northern shore?

The gulf in the Aegean Sea with Thessaloniki on its northern shore is the Thermaic Gulf.

The Thermaic Gulf occupies the northwestern corner of the Aegean Sea, in Greece. Thessaloniki stands at its northeastern tip, making the city the most prominent urban landmark associated with the gulf. The waterway is also called the Gulf of Thessaloniki or the Macedonian Gulf.

Its name comes from Therma, an ancient settlement identified with the area of modern Thessaloniki. Several rivers flow into the gulf, including the Axios (Vardar), Haliacmon, Loudias and Gallikos. Their sediments have gradually filled parts of the northern and western gulf; ancient Pella, once a coastal city, now lies inland.

A common mix-up is confusing the Thermaic Gulf with the nearby smaller Gulf of Salonica. Geographic definitions vary: some use “Thermaic Gulf” for the broader body of water, while narrower usage distinguishes the inner gulf around Thessaloniki. The Port of Thessaloniki is the gulf’s largest and busiest port.