Supportive social relations are crucial to wellbeing as young adults transition to independence, especially when these transitions are impeded by limited employment and educational opportunities, leading to lengthy 'waithoods'. Yet, there is limited empirical evidence on what young adults' support networks look like in highly resource-constrained settings. We therefore analysed the core support networks of 929 16-29 year-old rural South Africans to explore their social support landscape, using descriptive statistics and multilevel regression models. We found that these youth have small but intense support networks, with contacts often providing multiple types of support on a daily basis. While kin and parents are important support sources when present, parents are also frequently missing from these networks. Women received more intense support than men with more kin ties; men's networks contained more friends. While non-kin ties (friends and romantic partners) provide substantial support, they may also be unstable: for young men through dissolution following conflict and for young women due to the transactional nature of romantic relations. These findings imply that where work opportunities are scarce, young people's support networks are smaller and less parentally focused than elsewhere, potentially increasing their fragility and raising the risk of isolation.