Temperature is a fundamental ecological factor that shapes the expression of reproductive traits and the dynamics of sexual selection in ectothermic animals. This mini-review synthesizes current evidence on how thermal conditions influence sexually selected signals, mate preferences, reproductive behaviour, mating dynamics, gamete performance, and sex-specific reproductive responses across diverse ectotherm taxa. Available evidence indicates that temperature can modify visual, vibratory, acoustic, and colour-based sexual signals, while simultaneously altering female preferences and the degree of signal-preference coupling. Thermal variation may therefore either maintain or disrupt the correspondence between male signals and female choice, with important consequences for mating success. Temperature also constrains reproductive activity by modifying activity windows, thermoregulatory behaviour, courtship opportunities, and the allocation of energy to reproduction. Beyond pre-copulatory processes, thermal conditions affect sperm quantity and quality, sperm competition, fecundity, fertility, and post-copulatory sexual selection. Importantly, males and females may differ in their thermal sensitivity, producing sex-specific effects on reproductive success and potentially modifying the strength and direction of sexual selection. The evidence further suggests that thermal plasticity is often insufficient to compensate for rapidly changing thermal environments. Consequently, warming may generate mismatches between sexual signals, mate preferences, reproductive physiology, and environmental conditions, with implications for population viability and evolutionary adaptation. Understanding the reciprocal interactions between thermal ecology and sexual selection is therefore essential for predicting how ectothermic organisms will respond evolutionarily to ongoing climate change.
