Knud Leem (born 13 February 1697 – died 27 February 1774) was a Norwegian priest and linguist, most known for his work with the Sami people and the Sami languages.
Knud Leem was born in Haram in Møre og Romsdal county, Norway to parish priest Niels Knudssøn Leem and his wife Anne Danielsdatter Bugge. Leem started theological studies at Copenhagen University in 1713 and got his theological degree two years later at 18 years of age. He worked as a teacher and assistant to more senior priests until 1725 when he got a position as missionary for the Samis in Porsanger. In 1725 he moved back to southern Norway where he was appointed vicar in Avaldsnes He was appointed vicar in Alta in Finnmark during 1728. Dating from 1752, Leem headed the Seminarium Lapponicum Fredericianum in Trondheim until his death in 1774.
At the Seminarium Lapponicum, Knud Leem was assisted by Anders Porsanger in his work on a Sami dictionary. Leem had first started the linguistic study of Sámi when he published a grammar book in 1748. Between 1756 and 1768, he published two dictionaries. He also produced Lexicon Lapponicum Bipartituma, a trilingual lexicon to and from the Sami language into both Danish and Latin (1768–1781). Leem's grammar book shows an insight into Sámi that was not present in many other grammar books of the same era. Leem uses an inflection classification quite similar to the one being used today. He also commented on consonant gradation, but more as a tendency than as a rule.