Biharia euroregion (Romanian: Euroregiunea Biharia, Hungarian: Biharia Eurorégió) is a euroregion located in Romania and Hungary.

• Biharia euroregion is composed of:
  • Bihor County in  Romania
  • Hajdú-Bihar County in  Hungary
• The administrative center is Oradea which is the largest city of the euroregion.

City	Population	Metro	Country
Oradea	206,614	260,000	Romania
Debrecen	205,084	237,888	Hungary
Hajdúböszörmény	32,228	N/A	Hungary
Hajdúszoboszló	23,695	N/A	Hungary
Balmazújváros	18,615	N/A	Hungary
Hajdúnánás	18,185	N/A	Hungary
Salonta	18,137	N/A	Romania
Marghita	17,291	N/A	Romania
Berettyóújfalu	16,227	N/A	Hungary
Püspökladány	16,126	N/A	Hungary
Hajdúhadház	13,001	N/A	Hungary
Beiuş	12,089	N/A	Romania
Săcueni	11,665	N/A	Romania
Hajdúsámson	10,946	N/A	Hungary
Aleşd	10,852	N/A	Romania
Valea lui Mihai	10,317	N/A	Romania
Ştei	9,466	N/A	Romania
Derecske	9,086	N/A	Hungary