Erik Nissen Viborg (5 April 1759 – 25 September 1822) was a Danish veterinarian and botanist.
His studies of natural history introduced him to Peter Christian Abildgaard [da] who endorsed him to pursue a career in veterinary sciences.
After a year of study at the Cetenary School in Christianshavn, Viborg was employed as an assistant teacher with an annual salary of 200 Danish rigsdaler.
In 1796, King Christian VII of Denmark sent Viborg to Poland and Romania to purchase stallions for the Frederiksborg stud farm.
When the chair of botany was installed in 1797 at the University of Copenhagen, Viborg became its first holder, surpassing Martin Vahl.