The dualistic model of passion (Vallerand, 2015) distinguishes between harmonious and obsessive dimensions of passion. In sport, harmonious passion tends to be positively associated with adaptive sport outcomes, whereas obsessive passion tends to be positively associated with maladaptive sport outcomes. However, in the educational literature, both harmonious and obsessive passion have been linked with greater academic engagement. In this research, we tested if both passion dimensions were associated with greater levels of engagement in sport using the quadripartite approach (Schellenberg et al., 2019). We collected data from samples of athletes (N = 403) and coaches (N = 208) who completed online surveys assessing harmonious passion, obsessive passion, and different components of sport engagement (confidence, vigor, dedication, enthusiasm; Lonsdale et al., 2007). In both samples, results showed that all dimensions of engagement were positively associated with harmonious passion. In contrast, obsessive passion was negatively associated with vigor and enthusiasm (athlete sample), but positively associated with dedication (coach sample). Using a quadripartite approach, we found that the highest levels of dedication among coaches were for those with high harmonious passion and high obsessive passion, a result that supports findings in educational contexts. However, for all other engagement dimensions in both samples, the highest levels of engagement were associated with high harmonious passion, particularly when combined with low obsessive passion. These results mean that sport passion does not always translate into sport engagement; to achieve the highest levels of engagement, passion needs to involve high levels of harmonious passion.