The response surface method and process capability analysis were conducted in this study to improve evenness, hairiness, imperfections, and tensile strength of ring spun Supima cotton yarn by optimizing values of spinning parameters including traveler mass, yarn density, spindle speed, and yarn twist. The yarns were spun into three densities: 20 Ne, 30 Ne, and 38 Ne. An USTER Tester 5-S800 was used to evaluate the irregularity parameters of yarn. A Lloyd tester was also used to determine the yarn breaking load. The response surface method was applied to optimize the statistical values obtained from the tests of the yarns produced based on the combination values of system parameters. Each response was subjected to a response surface design study, and the optimal values were achieved by using a response optimizer to perform multiple response optimization. Interpreting the response surface design results yielded information such as the absolute values of effects, response degree of significance, data compatibility, and model suitability. Individual desirability, composite desirability, different estimates for each response, and the relationship between response and system variables were all revealed by interpreting the response optimization results. The capability indices of process capability analysis were used to compare process performance before and after response optimization. By interpreting the capability indices’ values of process capability analysis, the capability of the process to meet requirements and improvement potential were acquired. The data was analyzed by implementing Minitab software (Version 19).