Miercurea Nirajului (Hungarian: Nyárádszereda; German: Sereda, Neumarkt an der Njarad) is a town in Mureș County, central Transylvania, Romania. It administers seven villages: Beu, Dumitrești, Lăureni, Moșuni, Șardu Nirajului, Tâmpa and Veța.
It lies in the Székely Land, an ethno-cultural region in eastern Transylvania.
It formed part of the Székely Land region of the historical Transylvania province.
Its first written mention is from 1493 as Oppidum Zereda. István Bocskay was elected here for prince of Transylvania in 1604.
Until 1918, the town belonged to the Maros-Torda County of the Kingdom of Hungary. After the Treaty of Trianon of 1920, it became part of Romania.
| Historical population
|Source: Census data
The commune has a Székely Hungarian majority. According to the 2011 census, it has a population of 5,554 of which 83.3% are Hungarian, 10.4% Romanians and 6.3% Roma.