Janus Lauritz Andreas Kolderup Rosenvinge (November 7, 1858 - 1939) was a Danish botanist and phycologist. He took his Ph.D. 1888 from the University of Copenhagen. He was docent of botany at the polytechnic (Polyteknisk Læreanstalt) from 1900, and extraordinary professor of botany the University of Copenhagen with focus on spore plants from 1916. He undertook a suite of investigations of algae in Danish waters and in the North Atlantic.
The alga genus Rosenvingea Børgesen is named in his honour.