<p>Ecomorphological differences in postglacial fish exhibiting trophic polymorphism along the littoral-pelagic resource axis are well studied, but life-history traits remain far less explored across populations and lake types. We investigated life-history traits in European whitefish (<i>Coregonus lavaretus</i>) across 29 different mono- and polymorphic lakes spanning climate and productivity gradients in northern Fennoscandia. Four whitefish morphs—benthic LSR (large sparsely rakered), profundal SSR (small sparsely rakered), pelagic DR (densely rakered), and LDR (large densely rakered)—were analyzed alongside their congener vendace (<i>Coregonus albula</i>), encompassing 56 coregonid populations. We assessed how asymptotic length, growth rate, lifespan, age and length at maturity, gonadosomatic index, fecundity, egg size, and mortality associated with each morph varied among lakes with differing environmental characteristics. Polymorphic populations occurred only in large, cold, and low productivity lakes, monomorphic whitefish in similar but smaller shallow lakes, while productive and warmer lakes had vendace and monomorphic whitefish populations. Morphs exhibited significant life-history differences along the littoral-pelagic-profundal resource axis. Pelagic DR morph matured earlier and smaller, while benthic LSR morph displayed continued growth and longer lifespans along with LDR and SSR morph. Vendace, when present, resembled DR whitefish with higher fecundity and mortality. LSR morphs from monomorphic lakes showed the greatest variation, with values typically between pelagic and benthic morphs. Trophic morphology, particularly gill raker number and total length, were identified as the main drivers of life-history variation. The results suggest that life-history strategies are linked to feeding efficiency and specific habitat use, which may enhance morph fitness and promote divergence.</p> Graphic abstract <p></p>