The purpose of this study is to examine the effects of a distance learning course in critical thinking on the critical thinking skills and dispositions of university students. The diversification model was adopted in the study, which was carried out in line with the mixed research method, which combines the results of the data obtained by collecting both quantitative and qualitative data and allows comparisons to be made. The data of the study conducted with 30 senior university students were obtained with the "California Critical Thinking Disposition Scale" and open-ended questions about "What is critical thinking" and "Why is critical thinking important". Parametric and non-parametric analysis methods were used in the analysis of the quantitative data obtained from the data collection tools that were transferred to the online environment and applied to the participants before and after the critical thinking course. The content analysis method was used to analyze qualitative data gathered via open-ended questions. As a result of the analyses conducted, it was determined that there was a significant difference between the pre-test and post-test in terms of the participants' critical thinking dispositions. It was determined that there were no significant gender or departmental differences in the participants' critical thinking dispositions. As a result of the content analysis carried out within the framework of open-ended questions, it was determined that there were differences in the views of senior university students towards critical thinking before and after the critical thinking course. Within the framework of the results, it was suggested that more activities and practices for critical thinking should be included in undergraduate courses.