The modeling of one Dimensional Dispersion in Natural River Channels was targeted at developing an equation which can be applied in predicting longitudinal dispersion in natural river channels. Data in literature comprising 11 rivers and 29 sets of data consisting of hydraulic and geometric parameters were used to undertake a multivariate regression analysis which led to the development of the model equation. The relationships between the variables were investigated through the application of the Karl Pearson coefficient of correlation, while the accuracy of the model equation was ascertained through comparative analysis, discrepancy ratio and mean absolute error. The developed equation was further evaluated and analyzed by comparing its results with the experimental measured field data. A high degree of consistency was observed in the analysis which confirmed the suitability of the developed equation for calculating the one- dimensional dispersion values.