Bethlen is the name of two Hungarian ancient noble families, Bethlen de Iktár and Bethlen de Bethlen. Those two families do not have same ancestral roots, but both can trace their noble ancestry up to 12th and 13th century. It may refer to:
- Bethlen, son of Lőrinc, Hungarian nobleman, ancestor of the Bethlen and Apafi families
- András Bethlen de Bethlen (1847–1898), Hungarian Count who served as Hungarian Minister of Agriculture (1890–1894)
- Gabriel Bethlen de Iktár (1580–1629), Prince of Transylvania (1613–1629), Duke of Opole (1622–1625) and leader of an anti-Habsburg insurrection
- Katharina Bethlen de Iktár (1604-1649), Princess of Transylvania (1629-1630)
- Stephan Bethlen de Iktár (1582-1648), Prince of Transylvania in 1630.
- István Bethlen de Bethlen (1874–1946), Hungarian Count and statesman who served as Prime Minister of Hungary (1921–1931)
- János Bethlen de Bethlen (1613–1678), Hungarian aristocrat who served as Chancellor of Transylvania from 1659–1678.
- Farkas Bethlen de Bethlen (1639–1679), Hungarian Count who inherited his cousin as Chancellor of Transylvania from 1678–1679.
- Katalin Bethlen de Bethlen (1700–1759) Hungarian aristocrat and author
Bethlen is also the German and Hungarian name for Beclean, a town in Bistriţa-Năsăud County, Romania, while Betlen is the Hungarian and a German name for Beclean, a commune in Braşov County, Romania.