Purpose: The context personalization approach refers to matching educational content with characters, objects, and themes of students’ out-of-school interests. Considering the positive effects of individual interest on the regulation of student-in-context experiences, this study used the context personalization approach to match physical education (PE) lessons with students’ out-of-school interest for video games. The purpose was to explore the effects of a context personalization approach through a gamified PE unit on students’ interests and perceived competence. Method: One hundred and eighty-four students from eight PE classes were allocated to either an experimental group or a control group. All classes experienced a handball unit (six lessons), inspired by the Games-Centered Approach. The only difference between the experimental classes (N = 5) and the control classes (N = 3) was the presence or the absence of a context personalization approach centered on students’ out-of-school interest for video games. The effects were assessed on three outcomes variables: students’ individual interest, situational interest, and perceived competence. Results: The gamified PE unit resulted in positive effects on students’ individual interest, situational interest, and perceived competence in handball, since the experimental classes reported higher scores for all variables compared to the control classes. However, the effects on students’ situational interest were principally moderated by students’ individual interest, indicating that the effect of the context personalization approach was higher for the students having low preintervention individual interest. Discussion/Conclusion: Using a context personalization approach based on a gamified unit is a promising strategy in PE to impact students’ interests and perceived competence.