<p>Single-atom catalysts are isolated metal atoms on supports that offer well-defined active sites, nearly 100% atom utilization, and exceptional activity and selectivity, making them powerful platforms in heterogeneous catalysis. However, their uniform active sites often limit performances in complex chemical reactions involving multiple intermediates. To address this, integrative catalytic pairs (ICPs) are proposed, featuring spatially adjacent, electronically coupled dual active sites that function cooperatively yet independently. Unlike single-atom catalysts or dual-atom catalysts, ICPs offer functional differentiation within a small catalytic ensemble, enabling concerted multi-intermediate reactions. This Review traces the evolution from nanocatalysts to single-cluster catalysts and single-atom catalysts, evaluating their structural challenges and mechanistic limitations. Building on this, we define ICPs, illustrate their geometric and electronic features, and classify them by atomic composition and catalytic function. We highlight nitrate reduction, CO₂ conversion and hydrogenation reactions, in which ICPs exhibit enhanced activity and selectivity. We further outline advanced characterization strategies and artificial intelligence-assisted design frameworks for ICP discovery. Finally, we discuss the opportunities and challenges faced by ICPs in electrocatalysis, photocatalysis and green chemical synthesis.</p><p></p>