Multiple sequence alignment is one of the most widely used techniques in bioinformatics for discovering functional, structural, and evolutionary information of biological sequences. Multiple sequence alignment is NP-complete problem and a challenging area of bioinformatics. Classical approaches are not efficient for such type of problem because of the increased time and space complexities. Hence, enormous metaheuristic are being applied in this field. Particle swarm optimization is one of the best developed and popular metaheuristics employed for various application domains. This paper discusses the Particle swarm optimization variants and their applications for multiple sequence alignment.