Yngvar Nielsen (29 July 1843, Arendal, Aust-Agder – 2 March 1916) was a Norwegian historian, politician, geographer and pioneer of tourism in Norway.

[1] His grandfather, Jacob Nielsen,[2] had been one of Christiania's largest lumber dealers and director of the National Bank.

He was appointed manager of the University's Ethnographic Museum in 1877, and the following year he became research fellow in history and geography.

[citation needed] He had close connections to the royal family, and was the tutor of the Swedish princes Oscar and Eugen during their stay at the University of Christiania in the 1880s.

In 1879 he released the travel guide Reisehaandbog over Norge, popularly called Yngvar, which appeared in 12 editions until 1915 and came to play an important role in the spread of tourism.