HDMS Ingolf was a Danish schooner-rigged steam gunboat build in iron and launched in 1876.

Ingolf undertook a large number of voyages, often in the North Atlantic (Faroes, Iceland and Greenland) in summer and the Danish West Indies in winter.

Despite severe weather and ice conditions thousands of hydrographical measurements were taken and biological samples collected at a total of 144 stations, down to depths of 3500 meter.

The most significant results were the demonstration of two different bottom faunas separated by the Wyville Thomson Ridge south of the Faroe Islands and the systematic difference in temperature of the water at the sea floor between the north and south side of the ridge; and the very large number of small crustaceans collected by means of H.C. Hansen's method of filtering the bottom mud with fine silk gauze rather than a metal sieve.

A very large number of species of micro-crustaceans were thus described for the first time based on the material collected by the Ingolf expedition.