https://jjcit.org/paper/172 10.5455/jjcit.71-1652735477 Ibrahim Zebiri,Djamel Zeghida,Mohammed Redjimi Rat swarm optimization (RSO),Swarm intelligence,Cluster analysis,Clustering 7 5581 1615 1-Jun.-2022 27-Jul.-2022 18-Aug.-2022 Rat Swarm Optimizer (RSO) is one of the newest swarm intelligence optimization algorithms that is inspired from the behaviors of chasing and fighting of rats in nature. In this paper, we will apply the RSO to one of the most challenging problems, which is data clustering. The search capability of RSO is used here to find the best cluster centers. The proposed RSO algorithm for clustering (RSOC) is tested on several benchmarks and compared to some other optimization algorithms for data clustering, including some well- known and powerful algorithms such as Particle Swarm Optimization (PSO) and Genetic Algorithm (GA), as well as other recent algorithms, such as the Hybridization of Krill Herd Algorithm and harmony search (H-KHA), hybrid Harris Hawks Optimization with differential evolution (H-HHO) and Multi-Verse Optimizer (MVO). Results are validated through a bunch of measures: homogeneity, completeness, v-measure, purity and error rate. The computational results are encouraging, where they demonstrate the effectiveness of RSOC over other clustering techniques.