Jan Olof Lennart Olsson (pen name Jolo) (31 March 1920 – 30 April 1974) was a Swedish writer and a journalist for the Swedish newspaper Dagens Nyheter, where he elevated the short sketch to an art.

He was married to Margareta Sjögren, a journalist at another Swedish newspaper.

Olsson is known for his books about World War I and World War II, Den okände soldaten (1965; The Unknown Soldier) and Någonstans i Sverige (1974; Somewhere in Sweden).

[1] He has also written several historical essays and many travel books.

Olsson's writing is most notable for his ability to use vivid and picturesque situations to illustrate general patterns.