Person–Environment fit theory and research has been applied to many areas of organizational behavior such as career and job choice, selection, human factors, training, work commitment, turnover, and retirement transition. Approaches include obtaining separate measures of the person and the environment (atomistic approach), perceived discrepancies between the person and the environment (mechanistic approach), and direct estimates of subjective fit (molar approach). Studies variously focus on needs–supplies fit, abilities–demands fit, and supplementary and complementary fit. Fit theories most relevant to late‐career development and transition have emerged from the field of vocational psychology. Summaries are provided of several models including the theory of work adjustment (Dawis & Lofquist, 1984) and its application to retirement transition. Methodological issues are discussed, and ideas suggested for future research.