In the current study, the relationship between life satisfaction (LS) and the affective components of subjective well-being (SWB) was examined in a sample of 40,487 people across 21 European countries using data from the European Social Survey. After running multilevel confirmatory factor analyses in order to establish the measurement invariance of the constructs across the countries, the individual-level dataset was linked to available country-level aggregate personality traits, cultural values, and human development index (HDI). Results from hierarchical linear modeling (HLM) analysis showed that LS is best predicted by positive and negative affect (PA and NA, respectively), but may also be predicted by the degree of mixed emotions (ME). At the country level, national mean scores of Extraversion and Neuroticism moderated the relationship between LS and ME in different directions, whereas neither of the two personality traits had a significant impact on the relationship of LS to PA and NA. Survival/self-expression and the HDI ranking influenced the LS-PA and LS-ME relationships, whereas individualism/collectivism did not. Our research indicates that in addition to analyzing separate effects of NA and PA, it is also important to consider emotional complexity in SWB research, whereas these analyses need to take into account the moderating effect of cultural aspects, such as survival/self-expression values and countries’ level of development. Our findings also emphasize the importance of employing representative samples, as the age variance of participants can have a profound impact on results.