Johan Collett Müller Borgen (28 April 1902 – 16 October 1979) was a Norwegian writer, journalist and critic.

His best-known work is the novel Lillelord for which he was awarded the Norwegian Critics Prize for Literature in 1955.

He started his column which featured a series of ironic and satirical articles writing under the pseudonym "Mumle Gåsegg".

During the period 1947–59, he worked as a stage instructor in Oslo and instructed over forty performances.

Lillelord is the first book in the trilogy that also includes De mørke kilder and Vi har ham nå published in 1956 and 1957.