This chapter provides a synopsis of research on where multidimensional perfectionism "fits" within the broader framework of contemporary personality theory. Focusing on Hewitt and Flett's model of perfectionism—differentiating self-oriented, other-oriented, and socially prescribed perfectionism—the chapter presents a summary and critical discussion of how multidimensional perfectionism relates to the dimensions and facets of two major structural models of personality and one neuropsychological model of personality. The five-factor model (FFM) of personality is a structural model of personality that evolved from psycholexical analyses of traits followed by factor analyses. Another important structural model of personality based on psycholexical analyses is the HEXACO model. Consequently, the HEXACO model comprises six broad personality dimensions: honesty-humility (H), emotionality (E), extraversion (X), agreeableness (A), conscientiousness (C), and openness (O). The reinforcement sensitivity theory (RST) is a prominent neuropsychological theory of personality explaining individual differences in approach- and avoidance-related behaviors and associated conflicts.