Research on subjective well-being (SWB) goes back at least 90 years. Much of this research has been concerned with correlates and predictors of SWB. Much research has also been concerned with differentiating different types of SWB—specifically the distinction between hedonic well-being and eudaimonic well-being. This research shows that people can distinguish between activities and experiences that are more or less “meaningful” and “personally expressive” and those that are more or less enjoyable but that measures of “eudaimonic” well-being and measures of “hedonic” well-being are so highly correlated that they appear to be measuring the same construct. Research on theories of SWB strongly supports dispositional/construals theories that posit that SWB is primarily the result of inherited and learned predispositions to perceive and interpret life events in certain ways over life circumstance theories that propose that SWB is primarily the result of life events and life circumstances not mediated by interpretations of them. Among the problems with measuring subjective well-being and life satisfaction are lack of agreement on the conception of SWB (e.g., hedonic versus eudaimonic), an almost exclusive reliance on self-report measures, overreliance on correlational studies, a lack of consensus on how to measure SWB regardless of conception, and the tendency to reify scores on measures of SWB.