Jonas Danilssønn Ramus (27 September 1649 - 16 May 1718) was a Norwegian priest and historian. He was principally an author of religious and historical writings.
Ramus was born in Aukra, in Møre og Romsdal. His parents were Danil Johnsen Ramus (d. 1654), a parish priest and Anna Christensdatter Bernhoft (1624–1705). Ramus belonged a family of clerics, with the father, grandfather, stepfather and two brothers, clerics and scholars in various positions. He lost his father early, but her stepfather, Hans Olsen Brejer, took responsibility for his basic education. After studies at the Trondheim Cathedral School, in 1665 he was discharged to the University of Copenhagen with two of his brothers. For the next 15 years, he is believed to have continued studying in Copenhagen.
In the 1680s Ramus became the personal curate in Sørum kirke in Romerike under the priest Colbjørn Torstensen Arneberg. From 1690 Ramus was a priest in Norderhov kirke in Ringerike, in Buskerud County. Ramus became a magistrate in 1698.
In 1680, he published his first book, Naadens aandelige Markets-Tiid. It quickly became popular and was issued in both Swedish and Danish editions. Perhaps his best known book was Norges Beskrivelse which contains information about a feral child, Jostedalsrypa, the only survivor of the Black Death in her valley of Jostedal. Ramus also wrote about the famous Maelstrom at Moskenstraumen. His work was read by Edgar Allan Poe and mentioned in A Descent into the Maelström.
In 1682, he married Anna Colbjørnsdatter (ca. 1667- 1736), the daughter of pastor Colbjørn Torstensen Arneberg (1628–1720) in Sørum. They had five children: Ole (1683-1714), Daniel (1684-1727), Johanna (1685-1717), Christian (1686-1714) and Anna Sophie (1687-1722), all of whom were born in Sørum. Their son, Daniel Ramus followed his father as a priest in Norderhov from 1717, when his father was sick. Ramus died in 1718 at Norderhov.