GX113 – Grupo de Xadrez 113 is a chess club based in São Mamede de Infesta, Matosinhos, Portugal. Its aim is to make learning chess enjoyable and accessible, welcoming players of different ages and skill levels. The club offers an introductory chess course and learning resources, including chess databases, to support members as they develop their knowledge and playing skills.

GX113 also organises and participates in tournaments, including events in the União das Freguesias de São Mamede de Infesta e Senhora da Hora and team competitions. Its local tournaments bring together players for friendly, inclusive competition and have featured prizes across age groups and for teams. The club invites people to join and provides information about membership, its statutes, internal rules and activities through its website.

GX113 also shares chess games and commentary, helping enthusiasts explore practical play and strategy. The club lists a social gathering on Fridays at 21:00, subject to postponement. Its address is Rua Bernardim Ribeiro 166A, São Mamede de Infesta