Humans possess a desire to advance and accomplish (promotion focus) and to maintain security (prevention focus). Higgins’ (1997, 2000) regulatory fit theory proposed that the alignment between an individual’s regulatory focus and goal-pursuit strategies enhances their motivation and performance. Given the mixed findings in L2 learning concerning this hypothesis, this study investigates the mediating role of learner experience in regulatory fit effects. Utilizing the concept of flow as a framework for positive learner experience, the study examines the relationship between regulatory focus (promotion or prevention) and flow and further explores whether regulatory fit affects learners’ flow experience. Ninety university EFL students participated in activities designed to manipulate regulatory fit, and their flow experiences were assessed across three dimensions: intrinsic enjoyment, focused attention, and perceived control. Regression analyses were conducted to explore the relationships between regulatory focus, fit, and flow experiences. Findings indicated a positive correlation between promotion-focused regulatory orientation and all dimensions of flow, suggesting that learners with promotion focus experience greater enjoyment, attention, and perceived control in language learning tasks. However, contrary to expectations, regulatory fit did not significantly influence any dimension of flow. Findings are discussed in light of the applications of these concepts within L2 learning contexts.