This paper explores the use of natural coir fibers as a cost-effective and sustainable solution for liquefaction mitigation. Constant volume cyclic simple shear tests are carried out on natural river sand and sand with varying fiber content of 0.25%, 0.50%, and 0.75% by weight, and the results are compared. The influence of coir fibers on the generation of excess pore pressure, accumulation of shear strains, degradation of stiffness, and strain energy demand is quantified to compare the overall liquefaction response. Results showed that the liquefaction resistance increases by about 622% with the addition of 0.75% coir fibers to sand subjected to cyclic shearing with a peak-to-peak amplitude of 52 kPa and loading frequency of 0.20 Hz. Further, shaking table studies are carried out on sands with coir fibers to understand the large-scale applicability of coir fiber inclusions to mitigate liquefaction. The fundamental interactions between sand particles and coir fibers and mechanisms responsible for the beneficial effects of coir fibers are explained. The additional confinement effect generated through the stretching of coir fibers under applied forces is found to have a significant impact on creating a densification effect, thus leading to the overall enhancement of liquefaction resistance.