Hans Frede Nielsen (20 May 1943 – 9 January 2021) was a Danish philologist who was Professor Emeritus of Historical Linguistics at the University of Southern Denmark.

He received a Trinity College Foreign Bursary, which enabled him to earn a BA (1968) and MA in Anglo-Saxon Studies at Cambridge University.

Returning to Denmark, Nielsen worked as a high school teacher for several years.

He received his PhD in November 1980 with the thesis Old English and the Continental Germanic languages, which has subsequently been published in several editions.

In 1999, Nielsen was appointed Professor of Historical Linguistics at the University of Southern Denmark.