This volume constitutes the thoroughly refereed post-conference proceedings of the 6th International Conference on Swarm, Evolutionary, and Memetic Computing, SEMCCO 2015, held in Hyderabad, India, in December 2015. The 23 full papers presented in this volume were carefully reviewed and selected from 40 submissions for inclusion in the proceedings. The papers cover a wide range of topics in swarm, evolutionary, memetic and other intelligent computing algorithms and their real world applications in problems selected from diverse domains of science and engineering.