<p>Sequencing batch reactors are widely used for wastewater treatment, operating through sequential phases: filling, aeration, settling, and decanting. The settling phase critically influences performance, often leading to issues such as poor biomass separation and filamentous sludge bulking. This study developed an empirical model for the settling process of the sludge in operational basins of the reactors, which was further optimized by the Taguchi design method. Settling tests were conducted in 1L, 2L, and 4L beakers for the sludge samples collected from four different operational plants located at Ghaziabad, Haridwar, Patiala, and Rishikesh. Key input parameters included sludge volume index, zone settling velocity, and mixed liquor suspended solids, while the height of the settled sludge was the output. Analysis of variance was used to derive and validate the model equations. We believe that this integrated methodology—modeling, experimental validation, and optimization—enhances SBR efficiency and promotes sustainable wastewater treatment practices.</p>