Hector Frederik Estrup Jungersen (13 January 1854 – 6 March 1917) was a Danish marine zoologist born in Dejbjerg (today part of Ringkøbing-Skjern Municipality) .
From 1879 he taught classes at the Metropolitanskolen (Metropolitan School) in Copenhagen, where he served as an assistant professor from 1882 to 1899.
Jungersen was a proponent of evolutionary comparative morphology,[1] and is known for making significant contributions in the field of ichthyotomy (fish anatomy).
In 1895–96 he participated as a senior zoologist in the "Ingolf Expedition" to waters near Greenland and Iceland,[2] and afterwards carried out taxonomic investigations of marine fauna.
From the "Ingolf Expedition" he wrote an article on deep-sea marine life and its zoogeographical distribution.