Mangalia (Romanian pronunciation: [maŋˈɡali.a] ⓘ, Turkish: Mankalya), ancient Callatis (Greek: Κάλλατις/Καλλατίς; other historical names: Pangalia, Panglicara, Tomisovara), is a city and a port on the coast of the Black Sea in the south-east of Constanța County, Northern Dobruja, Romania.

The municipality of Mangalia also administers several summertime seaside resorts: Cap Aurora, Jupiter, Neptun, Olimp, Saturn, Venus.

Throughout the 2nd century AD, the city built defensive fortifications and the minting of coinage under the Roman emperors Septimius Severus and Caracalla continued.

According to Article XLVI the Bulgaria–Romania border in Dobrudja was defined as "a line starting from the east of Silistra and terminating on the Black Sea, south of Mangalia.

"[9] A Roman Byzantine building has been excavated against the city wall and next to a street paved with big limestone tiles and which has a channel on its longitudinal axis.

The resort has a large, fine-sand beach developed for purposes of aeroheliotherapy and wave therapy, as well as high seawalls with a specific microclimate where one may benefit from inhalations of saline aerosols having therapeutic effects.

At the 2021 census Mangalia had a population of 31,950 with a majority of Romanians (74.27%) and minorities of Tatars (3.07%), Turks (2.01%), Lipovans (0.19%), Roma (0.18%), Hungarians (0.13%), Bulgarians (0.01%), others (0.78%) and unknown (19.36%).