Purpose <p>Salinity is a major constraint on barley productivity, yet tolerance is dynamic and can be reshaped by repeated exposure through acclimation and stress‐memory processes.</p> Methods <p>This study evaluated a diverse barley panel across three successive generations (G1–G3) under salinity stress and corresponding controls to test whether salinity penalties on yield and key physiological and biochemical traits attenuate across generations and to identify trait modules and genomic regions underpinning resilient performance.</p> Results <p>Across generations, salinity-induced reductions in grain yield (GY) and sink traits, harvest index (HI), thousand-kernel weight (TKW), spikes per plant (SPP) and grains per spike (GPS) progressively weakened, consistent with improved yield stability in later generations. Physiological maintenance also strengthened from the first generation (G1) to the third generation (G3), as reflected by smaller stress-associated declines in relative water content (RWC) and stomatal conductance (gₛ), reduced elevation of canopy temperature (CT) and improved root performance, measured as maximum root depth (MRD). Concomitantly, injury markers, including electrolyte leakage (EL), malondialdehyde (MDA) and hydrogen peroxide (H₂O₂), showed reduced amplification. At the same time, osmotic and antioxidant defenses, including proline (Pro), total soluble sugars (TSS), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR), exhibited stronger activation in later generations. Ionic homeostasis improved in parallel, with reduced leaf sodium (Na⁺) accumulation and partial recovery of leaf potassium (K⁺) retention and the potassium-to-sodium ratio (K⁺/Na⁺), supporting a coordinated ion–reactive oxygen species (ROS)–water status resilience mechanism. Network analyses indicated a persistent positive module linking yield with hydration, ionic balance, antioxidant capacity, osmolytes and root depth, opposing an injury module dominated by Na⁺, EL, MDA, H₂O₂ and CT, with evidence for reduced injury-dominated covariance by G3. Genome-wide association mapping (GWAS) identified pleiotropic loci co-associated with yield resilience and homeostasis traits, prioritizing candidates in calcium (Ca²⁺) signaling, transporter regulation, ubiquitin-mediated proteostasis, small-RNA pathways and membrane/cell-wall remodeling.</p> Conclusions <p>Collectively, the generational attenuation of salinity penalties, reinforced defense activation, and convergent pleiotropic loci support a model of cross-generation stress imprinting and provide haplotype-scale targets for breeding barley cultivars with durable salt resilience.</p>