An attempt has been made in the present study to analyze the impact of shot peening on fatigue strength of Al-SiC (8 wt.%) composites. Composite samples prepared using stir casting method is machined to ASTM E466 standards and a portion of them are exposed to T6 heat treatments. Shot peening is done on various combinations of specimens and fatigue tests are carried out and compared. Fatigue strength of Al7075 is 156.5 MPa and it is found to be increased to 165.8 MPa for heat treated and shot peened Al-SiC composites. Design expert software is used for design of experiments in order to optimize the process parameters and enhance the fatigue strength of the specimens further. Fatigue strength of the specimens was increased to 174 MPa on repeating the test with optimized experimental parameters. The fatigue test results revealed that heat treated cum shot peened Al-SiC composite exhibited maximum results than other samples. Surface residual stress of the specimens are measured and is found that shot peening increases the compressive residual stress on the surface of the specimen. Surface roughness of the specimen is increased on shot peening. Microstructural analysis is done on the specimens to find the impact of shot peening on the surface of the composite specimens. The strengthening mechanisms of the composite samples are discussed with the help of microstructural images.