This study analyzes 2,617 10–15 year olds surveyed in wave 1 of the United Kingdom Household Longitudinal Study (UKHLS). Specifically, it tests the associations of three variables with life satisfaction among early adolescents: parent–child relationship quality, being a perpetrator or victim of sibling bullying, and being a perpetrator or victim of friend bullying. The results suggest that all of these social relationships have significant associations with life satisfaction, both individually and in combination. Of the three, parent–child relationship quality explained the most variance in predicting life satisfaction. This is followed by friend victimization (i.e., being bullied by friends), whereas the influence of sibling victimization is significant but not as strong. This study also tests the interaction effects between parent–child relationship quality, sibling bullying, and friend bullying. The association of parent–child relationship quality with life satisfaction is found to be stronger among adolescents who were either victims of sibling bullying or of friend bullying, highlighting the protective importance of parent–child relationship quality. Lastly, when testing whether the influences of sibling bullying, friend bullying, and parent–child relationship quality vary between male and female adolescents, this study finds some significant gender differences. Specifically, the positive associations of lower friend victimization and better parent–child relationship quality with life satisfaction are found to be stronger among female adolescents.