Peter Marcus Gjøe Rosenkrantz Johnsen (October 10, 1857 – September 16, 1929) was a Norwegian journalist and author.

[4] He passed his examen artium in Kristiania (now Oslo) in 1882, before he became the editorial secretary at the newspaper Bergens Tidende in 1883.

[4] When Henrik Ibsen and his wife Suzannah arrived in Kristiania on July 16, 1891, Johnsen was sent by Dagbladet, and that same afternoon the couple invited him for coffee at the Grand Hotel, where he interviewed them.

[5] Johnson covered the ceremony for the maiden voyage of RMS Lusitania in 1907 as a correspondent for Morgenposten.

Johnson made his literary debut in 1885 with the volume Nygifte og andre Smaafortællinger (Newly Married and Other Short Stories).