The two-volume set LNCS 11185 + 11186 constitutes the proceedings of the 10^th International Conference on Social Informatics, SocInfo 2018, held in Saint-Petersburg, Russia, in September 2018. The 30 full and 32 short papers presented in these proceedings were carefully reviewed and selected from 110 submissions. They deal with the applications of methods of the social sciences in the study of socio-technical systems, and computer science methods to analyze complex social processes, as well as those that make use of social concepts in the design of information systems.