The present work proposes a novel strategy to fabricate an integrated architecture of gel polymer elec-trolyte (GPE)–nanoarray cathode for lithium–O2 batteries (LOBs). As a proof-of-concept experiment, the photo-ini-tiated in situ polymerization of GPE was carried out via incorporating the precursor solution in advance into a self-standing binder-free oxygen electrode of Co3O4 nanosheets array grown on carbon cloth (Co3O4@CC), forming an integrated GPE–Co3O4@CC architecture. The perfor-mance of the solid-state LOBs using the GPE–Co3O4@CC assembly is greatly enhanced compared to the counterparts with a traditional cell structure, in which GPE was sand-wiched by a lithium metal and a cathode. The enhanced performance is ascribed to the combination of the in situ polymerization of GPE and the versatile structure of nanoarray electrode, which results in abundant interfacial contacts between GPE and electrode. This work presents an altative way to develop high-performance solid-state LOBs by combining the advantages of both gel polymer electrolytes and nanoarray electrodes.