Erhard Frederiksen (7 November 1843 - 12 October 1903) was a Danish agronomist and sugar manufacturer.
He is considered one of the most significant writers on agricultural economics of his time in Denmark.
He was in 1872-74 a co-founder of a sugar factory at Holeby on Lolland which was later taken over by the Danish Sugar Factories under the name Højbygaard Sugar Factory.