Issue AddressedSocial support is positively correlated with physical activity (PA), especially amongst girls, but is underexplored in male‐dominated action sports (e.g., mountain biking, skateboarding and surfing). This study explored family level social support needs and experiences of girls and boys in three action sports.MethodAspiring, current or former Australian adolescent (12–18 years; girls n = 25; boys n = 17) mountain bikers, skateboarders and/or surfers were individually interviewed (telephone/Skype) in 2018/2020. A socio‐ecological framework guided the semi‐structured interview schedule. Audio‐recordings were transcribed verbatim and data analysed thematically using a constant comparative approach.ResultsFamily level social support was highly influential in young people's participation in action sports, with its absence a common reason for no or discontinued engagement amongst girls. Parents and siblings were the main social support providers with extended family (e.g., grandparents, aunts/uncles, cousins) also notable. Participation (current/past/co‐) was the main social support type followed by emotional (e.g., encouragement), instrumental (e.g., transport, equipment/funding) and informational (e.g., coaching) support. Girls were inspired/encouraged by brothers but boys were not inspired/encouraged by sisters; boys and girls co‐participated with both parents but co‐participating and being inspired by fathers was most common, especially amongst girls; fathers were more commonly the main transport provider if they co‐participated with their child; fathers mostly provided initial coaching; only boys were taught equipment maintenance by parents.Conclusions and So WhatSport‐related organisations/groups have numerous opportunities to improve girls' representation in action sports by fostering family level social support through various means. Intervention strategies should be tailored to account for gendered participation differences.