Developmental theories have evolved toward emphasizing the totality of the organism, multiple levels of contexts, and dynamic interactions between the person and the environment and career development theories are no exceptions. Vondracek and his colleagues have introduced a developmental-contextual and systems-based framework of understanding vocational behavior and development and have also argued for the use of methodologies that align with such theoretical perspectives. However, research in vocational behavior and development is still dominated by variable-oriented approaches. Many studies rely on theories and methodologies that are variable-oriented: their focus is on relations between variables, interindividual differences, and are mostly based on aggregate-level analyses. In this chapter, six key principles of a person-oriented approach are discussed along with a few examples that correspond with each principle. Researchers are encouraged to apply and integrate a person-oriented approach in their research to enhance our understanding of vocational behavior and development.