In this article, square cyclone separator performance has been analyzed by varying the five important geometric parameters. Primarily, Swift (1971) model is considered to develop the mathematical square cyclone. Body height and inlet height, total height, inlet width and outlet diameter are the controlling parameters considered for governing the responses namely cut-off diameter and pressure drop. The L27 orthogonal array is developed using Taguchi Robust Design. Based on the design matrix, the regression equation is developed for the two responses. The quality of the equation arrived has been validated by ANOVA followed by optimization using multi-objective genetic algorithm approach. The optimal results are identified through the Pareto approach. The optimization results are validated by experimental analysis. Numerical simulation is performed to obtain the flow pattern and separation efficiency. The final result confirms that the optimum square cyclone produces the enhanced performance. (C) 2020 Elsevier B.V. All rights reserved.