Blaj is a city in Alba County, Transylvania, Romania.

The landmark of the city is the fact that was the principal religious and cultural center of the Romanian Greek-Catholic Church in Transylvania.

Blaj lies at the confluence of the two Târnava Rivers, in a wine-growing region. The city has a continental temperate climate, characteristic for the Transylvanian Plateau, with moderate precipitations of around 550 mm/mp.

Blaj is first mentioned in 1271 as Villa Herbordi, after the deed of a Count Herbod. In 1313, the domain passed to Herbod's son Blasius Cserei. Started as a hamlet for the twenty families of servants of the noble's court, it was awarded town status on May 19, 1737.

Blaj is the principal religious and cultural center of Greek Catholics in Transylvania. At 27 October 1687 begins the history of the Church United with Rome, Greek-Catholic, history directly connected to the history of the town Blaj. It all started at the end of the treaty through which Transylvania was entering under the protection of Austria, renouncing the protection of the Turkish Empire.

The first public school in Romanian was established in Blaj in 1754. Blaj was the first place to have Romanian written with Latin alphabet instead of the Cyrillic alphabet in which it had traditionally been written. Blaj was also a center for the Romanian Age of Enlightenment, being the founding site of the Şcoala Ardeleană society that promoted the Roman cultural heritage of the Romanians. Thus Blaj gained the nickname "The Little Rome".

Sights:

• The castle of the Bethlen dynasty is a popular tourist site near Blaj. 
• the Metropolitan Palace,
• the Holy Trinity Cathedral,
• the "Buna Vestire" Monastery,
• the Greeks' Church,
• the "Liberty Field",
• Mihai Eminescu's linden tree, and
• Avram Iancus oak.