Given the growing trend of using high-strength steels in civil structures, fatigue in the weld zone of these steels has become one of the major challenges in the design and operation of structures. The use of nanomaterials in welding high-strength steels is considered a novel approach to increase fatigue resistance and improve the microstructure of joints in transportation infrastructure, significantly enhancing the service life of structures against cyclic loads. The welding process significantly reduces fatigue resistance due to stress concentration, metallurgical changes, and the presence of local defects. Various solutions have been proposed to mitigate this problem, among which nanotechnology has emerged as a novel strategy for increasing weld durability. In this research, by reviewing over 30 scientific sources, the role of various nanoparticles such as TiC, TiO₂, SiC, Al₂O₃, and CNT in improving the mechanical properties of welds has been investigated. Furthermore, the effects of hybrid methods such as friction stir welding (FSW), HFMI surface treatments, and nanostructured metallic coating (NMM) on the fatigue of welded structures have been analyzed. The results of this systematic review indicate that by using nanomaterials and modern welding methods, significant improvements in fatigue resistance, reduction of crack growth rate, and increase in the service life of welds under cyclic loading conditions can be achieved. Nanoparticles make the grain structure more uniform by creating homogeneous nucleation sites and prevent the growth of coarse grains. Additionally, methods for inducing surface compressive stress, such as shot peening, play an effective role in neutralizing residual tensile stresses and increasing fatigue life. Welding parameters, including tool rotational speed, travel speed, and the number of passes, have a significant impact on the uniform distribution of nanoparticles and preventing their agglomeration.