Lorentz Henrik Segelcke Dietrichson (1 January 1834 Bergen - 6 March 1917) was a Norwegian poet and historian of art and literature.

Dietrichson grew up in Bergen as an only child in a home of cultural officials interested in the parents' social circle.

After school graduation in 1853 at the University of Christiania and other exams the following year he began to study theology, but he was more keen to cultivate their literary and artistic interests.

For a time he served as instructor at Uppsala University and subsequently for three years was secretary to the Norwegian minister at Rome.

After examining Danish and Swedish 18th century literature, he published two-volume Omrids af den norske Poesis Historie (1866-1869).