In second language education, the flipped classroom has been widely researched and increasingly applied as a teaching approach to improve the academic performance and engagement of English as a foreign language learners. However, learner engagement is a multidimensional construct, and not much empirical evidence exists about whether the flipped classroom can lead to a significant improvement in learners’ behavioural, emotional, cognitive, and social engagement in the EFL class. To fill this gap, this study adopted a mixed-methods research approach to evaluate the impact of the flipped College English Listening and Speaking class on four-dimension learner engagement in a mainland China context. After an eight-week intervention we compared the experimental group (the flipped class, N = 34) and the control group (the non-flipped class, N = 35). Findings demonstrate that after eight weeks of flipped instruction, students in the flipped class achieved higher mean scores on the post-test engagement questionnaires in behavioural, emotional, cognitive, and social engagement. However, the difference in emotional engagement between the flipped and non-flipped classes was not statistically significant. Semi-structured interviews revealed several factors responsible for learner engagement in the flipped EFL classroom. Positive influencing factors were learning environment, instructor presence, learning content, and learner presence, whereas negative aspects included the excessive workload on learners, lack of learning preparedness, lengthy videos, and technical challenges. Based on the findings, we would argue that the instructor and other educational stakeholders should provide more support to cater to learners’ emotional engagement and help learners cope with the challenges encountered throughout the flipped learning process. The study may assist teaching professionals and researchers obtain a clearer understanding of flipped instruction in the EFL context and design and implement the flipped class by considering the positive and negative elements affecting learner engagement.