Kalniņš (Old orthography: Kalnin(g); feminine: Kalniņa) is a native Latvian-language topographic surname, derived from the Latvian word for "hill" (kalns). May also be Russified as Kalnin (Калнин, Калнынь). Notable people with the surname include:

Kalniņš
Origin
Word/nameLatvian
Meaning"little hill"