Bouchelaghem, F.Boulares, H.Ardjouni, A.Jarad, F.Abdeljawad, T.Abdalla, B.Shah, K.2025-05-132025-05-1320252666-8181https://doi.org/10.1016/j.padiff.2025.101104https://hdl.handle.net/20.500.12416/9776Recently, the field of fractional calculus has garnered significant attention due to its wide range of applications across various disciplines in science and engineering. Numerous results have been derived using tools from numerical functional analysis and fixed point theory to address a variety of problems in this area. This study employs the Banach Fixed Point Theorem (BFPT) to establish the existence and uniqueness of solutions for Riemann–Liouville fractional differential equations (RLFDEs) involving multiple orders. Sufficient conditions for the existence of solutions to the problem under consideration have been provided. Furthermore, an illustrative example is presented to validate the theoretical findings. © 2025eninfo:eu-repo/semantics/openAccessBanach Fixed Point TheoremsExistenceMulti-OrderRiemann–Liouville Fractional DerivativesUniquenessArticle1310.1016/j.padiff.2025.1011042-s2.0-85217399115N/AQ1