Pehr Kalm (6 March 1716 – 16 November 1779) (in Finland also known as Pietari Kalm and in some English-language translations as Peter Kalm) was a Swedish-Finnish explorer, botanist, naturalist, and agricultural economist. He was one of the most important apostles of Carl Linnaeus. Among his many accomplishments, Kalm can be credited for the first description of Niagara Falls written by someone trained as a scientist.