A method for producing monocyclic aromatic hydrocarbons of 6 to 8 carbon number from a feedstock oil containing polycyclic aromatic hydrocarbons and saturated hydrocarbons and having a 10 volume % distillation temperature of at least 140°C and a 90 volume % distillation temperature of not more than 380°C, the method comprising: a cracking and reforming reaction step of bringing the feedstock oil into contact with a monocyclic aromatic hydrocarbon production catalyst comprising a crystalline aluminosilicate to cyclize and dehydrogenate the saturated hydrocarbons and to partially hydrogenate the polycyclic aromatic hydrocarbons using a hydrogen transfer reaction from the saturated hydrocarbons, thereby obtaining a product comprising monocyclic aromatic hydrocarbons of 6 to 8 carbon number, a refining and collection step of refining and collecting monocyclic aromatic hydrocarbons of 6 to 8 carbon number that have been separated from the product obtained in the cracking and reforming reaction step, a hydrogenation reaction step of hydrogenating a heavy fraction of 9 or more carbon number separated from the product obtained in the cracking and reforming reaction step, a recycling step of returning a heavy fraction hydrogenation reaction product obtained in the hydrogenation reaction step to the cracking and reforming_reaction step, a hydrogen recovery step of recovering, from the product obtained in the cracking and reforming reaction step, hydrogen that is produced as a byproduct in the cracking and reforming reaction step, and a hydrogen supply step of supplying the hydrogen recovered in the hydrogen recovery step to the hydrogenation reaction step, wherein the monocyclic aromatic hydrocarbon production catalyst includes at least one of phosphorus, boron, gallium, and zinc, and wherein there is no supply of hydrogen from an external source. a cracking and reforming reaction step of bringing the feedstock oil into contact with a monocyclic aromatic hydrocarbon production catalyst comprising a crystalline aluminosilicate to cyclize and dehydrogenate the saturated hydrocarbons and to partially hydrogenate the polycyclic aromatic hydrocarbons using a hydrogen transfer reaction from the saturated hydrocarbons, thereby obtaining a product comprising monocyclic aromatic hydrocarbons of 6 to 8 carbon number, a refining and collection step of refining and collecting monocyclic aromatic hydrocarbons of 6 to 8 carbon number that have been separated from the product obtained in the cracking and reforming reaction step, a hydrogenation reaction step of hydrogenating a heavy fraction of 9 or more carbon number separated from the product obtained in the cracking and reforming reaction step, a recycling step of returning a heavy fraction hydrogenation reaction product obtained in the hydrogenation reaction step to the cracking and reforming_reaction step, a hydrogen recovery step of recovering, from the product obtained in the cracking and reforming reaction step, hydrogen that is produced as a byproduct in the cracking and reforming reaction step, and a hydrogen supply step of supplying the hydrogen recovered in the hydrogen recovery step to the hydrogenation reaction step, wherein the monocyclic aromatic hydrocarbon production catalyst includes at least one of phosphorus, boron, gallium, and zinc, and wherein there is no supply of hydrogen from an external source.