This chapter presents a theoretical model on the importance of interests to understand retirement. It discusses interests to be likewise important antecedents for older adults’ retirement choices and career exit decisions and the roles of both vocational and leisure interests for understanding retirement. The psychological perspective on retirement as a temporal process emphasizes putting the research focus on individual differences as antecedents of retirement. Concatenating the largely unconnected literatures on interests and retirement, the present chapter provides a theoretical model on the importance of interests for understanding retirement. The transition from work to retirement involves significant changes in how persons spend their time. Comparable to vocational choices in young adulthood, when deciding to take bridge employment, the choice of a specific bridge employment is likely to be in accordance with one’s vocational interests in terms of content. Retirement depicts one of the major life course transitions and is characterized by ongoing changes in peoples’ circumstances and activities.