This study investigated the impact of the critical inquiry model through peer feedback strategies in an online environment on university students' critical thinking skills and examined their attitudes towards learning through the critical inquiry model and peer feedback strategies. Pre-and post-tests were employed to measure critical thinking skills based on Bloom's questioning cognitive levels, together with a rubric designed to assess significant abilities involved in critical thinking in a domain-explicit manner. A questionnaire was used to investigate students' attitudes. The findings reported an increase in the post-test mean scores, showing that the application of the critical inquiry model and peer feedback strategy can promote critical thinking skills. Results from the questionnaire suggested that students who used the critical inquiry model to provide peer feedback had favorable attitudes toward learning, higher levels of motivation, and increased levels of confidence when using discussions with peers in an online forum.