This study is aimed at investigating the effects of flipped learning on self-directed learning attitude in the college setting. For the aim, this study tried to see if there are meaningful changes in learners’ self-directed learning attitude over time. With the research aim in mind, an elective university class of 47 students was observed for 15 weeks. A survey questionnaire was developed from Guglielmino(1977)’s characteristics of self-directed learning attitude, and four characteristics were finally used for this study: Openness, self-directedness, responsibility, and passion for learning. The questionnaire was administered twice in the 5th and 14th weeks, followed by in-depth interviews with 9 participants. A non-parametric test for repeated t-test, Wilcoxon matched pairs signed rank test was used for data analysis. The research findings are as follows. First, the results of the questionnaire indicated that there were statistically meaningful changes in all 4 characteristics of learners’ self-directed learning attitude before and after flipped learning. Second, the analysis of in-depth interviews revealed that students felt positive about their flipped learning since it provided them with great opportunities to develop and strengthen their self-directed learning attitude. Implications and suggestions for further research are provided.