This paper introduces and investigates the Nabla discrete Sawi transform, with a focus on its mathematical properties and its application to solving fractional difference equations. The study demonstrates how the transform effectively manages fractional sums and differences, providing a robust framework for addressing initial value problems. Notably, it is shown that the discrete Mittag-Leffler function acts as the eigenfunction of the Caputo-type fractional difference operator \( \nabla _\alpha \) under the Sawi transform. This work not only advances the understanding of fractional calculus in the context of discrete systems but also highlights the potential of the Nabla discrete Sawi transform across various fields, including engineering, physics, and biology. The results underscore the transformative power of this approach in solving complex fractional calculus problems, offering both theoretical insights and practical applications.