thumb|right|200px|Schooner Fylla in Copenhagen harbour
Carl Hartvig Ryder (12 September 1858 – 3 May 1923) was a Danish naval officer and Arctic explorer.
Carl Ryder was born in Copenhagen. He was the son of Frederik Valentiner Ryder (1821-1909) and his wife Henriette Sophie Cathrine Husmann (1836-1896). He entered a military career in the Royal Danish Navy becoming a Second Lieutenant in 1879 and Captain 1897.[1]
He led an expedition to the Upernavik Distrikt in 1886-1887 and, most famously, the 1891-1892 expedition to East Greenland by the vessel Hekla. The way north from Ittoqqortoormiit was effectively blocked by ice. Instead, Ryder made the first comprehensive mapping of the entire Scoresby Sund fjord system, except for the inner part of Nordvestfjord.[2]
He was a member of several other expeditions:
He married Ida Caroline Helene Clara Wolff (1864–1933) in 1888.[4]
The Ryder Glacier in NW Greenland is named in his honour.