In this study, crosslinked sulfonated poly(ether ether ketone) (SPEEK) membranes containing various amounts of zirconium phosphate (ZrP) particles were fabricated using an electron beam irradiation method. The water uptake and IEC value of the crosslinked SPEEK/ZrP hybrid membranes were higher than those of crosslinked SPEEK membranes and increased with an increase in ZrP content. Furthermore, under high temperature and low humidity conditions (120°C and RH 35%), the crosslinked SPEEK/ZrP hybrid membrane exhibited a higher proton conductivity (1.41 × 10−3 S/cm) compared with the crosslinked SPEEK membrane (1.13 × 10−4 S/cm). POLYM. COMPOS., 39:1905–1912, 2018. © 2016 Society of Plastics Engineers