= 53) using the non-equivalent group pretest-posttest design, followed by a program satisfaction survey. This study is meaningful in that it developed an online program to help college students improve career adaptability and identified its effectiveness. This study yielded two results. First, it successfully developed a career adaptability improvement program for undergraduate students, wherein the career development tasks, and the sub-factors of career adaptability were organically interlinked. Second, it verified the statistically significant differences in the career adaptability scores among the experimental, comparison, and control groups. The highest mean score was obtained by participants in the experimental group, followed by the comparison and the control group.