A method for producing a monocyclic aromatic hydrocarbon of the present invention includes a cracking and reforming reaction step of obtaining a product containing a monocyclic aromatic hydrocarbon having 6 to 8 carbon atoms by bringing a feedstock oil having a 10 volume % distillate temperature of 140° C. or higher and a 90 volume % distillate temperature of 390° C. or lower and a saturated hydrocarbon having 1 to 3 carbon atoms into contact with a catalyst for producing a monocyclic aromatic hydrocarbon containing crystalline aluminosilicate, which is loaded into a fixed-bed reactor, and reacting the feedstock oil and the saturated hydrocarbon.