Rice is a key food crop worldwide, but its yield and quality are severely constrained by insect pests. As environmental and regulatory restrictions on chemical pesticides grow, developing insect-resistant rice varieties has become a sustainable way to protect food security. This review covers recent progress in functional genomics and molecular marker mapping related to insect resistance in rice. We highlight the identification, cloning, and functional analysis of resistance genes targeting major pests, including the brown planthopper, rice gall midge, white-backed planthopper, small brown planthopper, and rice leaf roller. Several important resistance genes (such as Bph14, Bph3, and Bph29) have been cloned, and their roles in rice immunity have been clarified—covering insect feeding signal recognition, activation of salicylic acid and jasmonic acid pathways, and regulation of MAPK cascades, calcium signaling, and reactive oxygen species production. We also discuss how molecular marker-assisted selection, gene pyramiding, and transgenic techniques are used in modern rice breeding. Finally, we address future challenges and opportunities, stressing the importance of utilizing wild rice germplasm, understanding insect effector–plant immune interactions, and applying molecular design breeding to create long-lasting insect-resistant rice varieties that can withstand changing pest pressures and climate conditions.