Distinctive cortico-striatal circuits that serve motor and cognitive functions have been recently mapped based on resting state connectivity. It has been reported that age differences in cortico-striatal connectivity relate to cognitive declines in aging. Moreover, children in their early teens (i.e., youth) already show mature motor network patterns while their cognitive networks are still developing. In the current study, we examined age differences in the frontal-striatal "cognitive" and "motor" circuits in children and adolescence, young adults (YAs), and older adults (OAs). We predicted that the strength of the "cognitive" frontal-striatal circuits would follow an inverted "U" pattern across age; children and OAs would have weaker connectivity than YAs. However, we predicted that the "motor" circuits would show less variation in connectivity strength across the lifespan. We found that most areas in both the "cognitive" and "motor" circuits showed higher connectivity in YAs than children and OAs, suggesting general inverted "U"-shaped changes across the lifespan for both the cognitive and motor frontal-striatal networks.