<p>The concentration distribution of sediment particles in open-channel turbulent flows plays a crucial role in understanding sediment transport processes. The present research utilizes fractional entropy, which is based on the concept of a fractional derivative, to derive the vertical profile of suspended sediment concentration in open-channel flow. In the first case, fractional entropy, together with the principle of maximum entropy, is explored to infer the most probable and unique probability distribution for sediment travel distance among all other distributions satisfying the same set of constraints. In the second case, a one-dimensional random walk model (Fokker–Planck equation) governed by a nonlinear differential equation is derived to model the movement of sediment particles probabilistically, assuming the release of sediment particles as a point source. The resulting distribution closely aligns with the one derived through entropy principles. Next, a cumulative distribution function in the spatial domain is proposed to relate sediment concentration to the spatial variable. The derived sediment concentration profile is validated against relevant experimental and field data, showing good agreement between computed and observed values. This study suggests an alternative approach to modeling sediment transport processes in open channels.</p>