Membrane bioreactors (MBRs) integrate membrane separation with activated-sludge processes and are increasingly employed in wastewater treatment. Despite their advantages, MBRs can suffer from limited mass-transfer efficiency and operational instability. Advanced oxidation processes (AOPs) generate highly reactive species that enable rapid contaminant degradation, but their practical use is constrained by high energy demand and the potential for secondary pollution. Combining MBRs with AOPs therefore leverages membrane filtration, biological degradation, and oxidative destruction of recalcitrant compounds, providing a promising strategy for treating high-strength wastewaters. This review summarizes recent progress in MBR–AOP hybrid systems, including photocatalytic MBRs (ICPB), electro-catalytic MBRs (EMBR), integrated photo-/electrocatalytic MBRs, MBR-Fenton, and MBR-ozonation configurations. The various hybrids are compared in terms of catalyst selection, operational advantages, removal performance, and application scope. Current structural, operational, and scale-up challenges are discussed, and future research directions for MBR–AOP technologies are proposed.