Near Oceanic populations harbor remarkable cultural, phenotypic, and genetic diversity, yet are drastically underrepresented in human genomics. We generated 177 high-coverage Near Oceanian whole genomes and analyzed them alongside 1,284 worldwide genomes, revealing major distinctions among and within islands including long-term isolation and strong population bottlenecks. We reconstructed 1.897 Gbp of the archaic genome including 831.9 Mbp of Denisovan sequence, found evidence for introgression from three Denisovan-like groups in Near Oceanians, and adaptive Denisovan introgression at TRPS1, a skeletal development gene also under selection in central African rainforest hunter-gatherers and highland Ecuadorians. We then performed a massively parallel reporter assay and discovered 3,127 high-frequency introgressed expression-modulating variants, finding an enrichment of functional impacts on genes in the IFNγ signalling pathway including JAK1, GBP2, and OAS1.