This paper investigates the effects of different dimensions of social capital (i.e., trust, social network and norms of civic engagement) on subjective well-being (SWB) at the individual level by attending to differences between the extremes of SWB distribution, that is, between the happiest and the unhappiest people. To this end, we use the 7th wave of the 2014 European Social Survey to run a quantile regression analysis to investigate whether any of these dimensions of social capital has a heterogeneous effect on the full distribution of well-being. We also perform a factor analysis to summarize the principal components of these three dimensions. Our results show that each dimension of social capital has a positive and significant correlation with SWB, but the different dimensions have a heterogeneous effect on the different quantiles of the well-being distribution. All of these dimensions of social capital have a stronger effect on the SWB of the least happy people in society than on the happiest.