Cyrillus Gustave Emile "Cyriel" Buysse (pronounced [siˈril ˈbœysə]; 20 September 1859 – 25 July 1932) was a Flemish naturalist author and playwright.

Buysse became known as a naturalist writer in the tradition of Stijn Streuvels, Émile Zola and Guy de Maupassant.

Buysse married the Dutch widow Nelly Dyserinck in 1896 and spent winters in The Hague in the Netherlands, where his son René Cyriel was born in 1897, while staying at his rural estate in Afsnee in Belgium during summer.

In 1903, he co-founded another literary magazine, Groot Nederland together with Louis Couperus en Willem Gerard van Nouhuys which he continued to edit until his death.

In 1932 he was ennobled by King Albert I to the rank of baron, which was then a rare honour for a writer, and ironic given the tone and subject of his books; since he died four days later he was not able to receive the appropriate letters patent and so was unable to use the title.