A back side protective sheet for a solar cell, which is capable of enhancing performance of adhesion to an EVA resin as a filler used to seal solar cell elements, maintaining weather resistance for a long period of time, and reducing weight thereof; and a solar cell module including the back side protective sheet for a solar cell. The back side protective sheet is disposed on a back side of the solar cell module and includes: a first film fixedly attached so as to abut a surface of a filler and containing linear low-density polyethylene having a density greater than or equal to 0.91 g/cm3 and less than or equal to 0.93 g/cm3; and a second film laminated to the first film and disposed in an outermost layer of the back side protective sheet, the second film containing polyvinylidene fluoride and polymethyl methacrylate.