Samnangjin (also spelled Samrangjin) or Samnangjin-eup, is an eup, or town, in Miryang City, Gyeongsangnam-do, South Korea.

Samnangjin lies in the southeastern corner of Miryang, bordering Wondong-myeon in Yangsan City.

The Gyeongbu Line railroad passes through Samnangjin, and Mugunghwa-ho class passenger trains frequently stop there.

Much of the land in Samnangjin lies along the eastern valleys of these two rivers, which also form the western border of the eup.

Notable mountains on the borders of Samnangjin include Cheontaesan to the south and Maneosan to the north.