Helmer Hermansen (1 February 1871, Løten – 19 March 1958) was a Norwegian rifle shooter who competed in the early 20th century in rifle shooting.
He participated in Shooting at the 1900 Summer Olympics in Paris and won the silver medal with the Norwegian Military Rifle team.
In the same Olympics he also participated in the following events:
military rifle, standing - ninth place
military rifle, prone - tenth place
individual rifle, three positions - 13th place
military rifle, kneeling - 13th place