Cuprous　oxide　(Cu2O)-based　photocathodes　have　been　attracting　enduring　interest　for　green　and　sustainable　solar　fuel　production　by　solar-driven　photoelectrochemical　(PEC)　water　splitting　and　CO2　reduction　reactions.　Although　Cu2O　is　featured　by　the　theoretically　outstanding　photoactivity　owing　to　the　favorable　band-gap　and　appropriate　band　alignment,　wide-spread　utilization　of　Cu2O　is　largely　hampered　by　its　severe　photo-corrosion　and　difficulty　in　charge　transfer/separation　modulation,　hence　rendering　fabricating　robust,　stable　and　high-efficiency　Cu2O-based　photoelectrodes　a　continuously　challenging　issue.　In　this　review,　fundamentals　of　PEC　reactions　including　water　splitting　and　CO2　reduction　are　concisely　elucidated,　and　then　diverse　strategies　for　constructing　a　large　variety　of　quintessential　Cu2O-based　photocathodes　are　comprehensively　summarized.　Subsequently,　predominant　Cu2O-based　photocathodes　currently　being　extensively　explored　in　PEC　water　splitting　and　CO2　reduction　reactions　are　specifically　introduced.　Finally,　future　perspective　and　outlook　of　Cu2O-based　photocathodes　in　these　two　booming　research　fields　are　forecasted.　Our　review　could　provide　enriched　information　on　rational　design　and　utilization　of　Cu2O-based　photocathodes　for　solar　fuel　production.　©　2022　Elsevier　B.V.