This chapter explores the enhancement of fatigue resistance in strain-hardening cement-based composites (SHCC) through a combined experimental and numerical approach. The studies at hand focussed on investigating fibre-matrix interactions, crack propagation, and damage mechanisms. Experimental tests, such as uniaxial tension, pull-out, and relaxation tests, were conducted to understand SHCC’s mechanical behaviour subjected to different environmental and loading conditions. These findings were compared to numerical simulations using the microlayer approach, fibre super-element, cohesive interface models and phase-field fracture, which simulate complex behaviours like fibre pull-out and crack formation. To address the computational challenges of simulating high-cycle fatigue, time homogenisation techniques were used to reduce the number of calculations required. The results show strong agreement between experimental data and numerical simulations, highlighting the effectiveness of the multiscale modelling approach. The findings of the studies presented in this chapter contribute to advancing the understanding of the fatigue behaviour of these composites and provide practical insights for developing more durable, fatigue-resistant materials for infrastructure exposed to cyclic stresses, setting a precedent for improving multiscale material design approaches.