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: Alfrēds Kalniņš, Latvian composer Brūno Kalniņš, Latvian social democratic politician and historian Eduards Kalniņš, Latvian general. Gatis Kalniņš, Latvian striker , German-Latvian bishop Imants Kalniņš, Latvian composer Ivars Kalniņš, Latvian film and television actor Jānis Kalniņš, Canadian composer, son of Alfreds Jānis Kalniņš, Latvian ice hockey goaltender Klāra Kalniņa (1874–1964), Latvian feminist, suffragette, editor, and politician Leonīds Kalniņš (born 1957), Latvian politician and general Ojārs Ēriks Kalniņš (1949–2021), Latvian politician and diplomat Pauls Kalniņš, Latvian social democratic politician and four-time acting president Pēteris Kalniņš, Latvian luger Rodrigo Kalniņš, Latvian actor Rolands Kalniņš, Latvian film director Rēzija Kalniņa, Latvian actress Zanda Kalniņa-Lukaševica, Latvian politician Latvian toponymic surnames Latvian-language masculine surnames