The purpose of this quantitative correlative study was to determine what, if any, statistically significant correlations exist between undergraduate STEM students' perception of transactional distance and their level of engagement in an online learning environment at two-year community colleges. The theoretical foundations for the study included the theory of transactional distance and the community of inquiry model. The study included three research questions, each of which was examined separately. The questions focused on the relationship between transactional distance--student-to-teacher, student-to-student, and student-to-content--with online student engagement. In all cases, the hypotheses stating no significant correlation were rejected, which indicates statistically significant correlations. The researcher used a sample size of n = 160 community college students in the US who had taken STEM-related courses online in the last six months. Data were collected using the Revised Survey of Transactional Distance and the Online Student Engagement Survey. Spearman correlation analysis revealed significant correlations between transactional distance and student engagement in all tested dimensions with p [less than or equal to] 0.05 in each of the tests. Each of the relationships included a r [greater than or equal to] 0.40, which indicates that the strength of the correlations was at least moderate strength and a positive direction. The higher scores on the instrument were an indication of lower perceptions of transactional distance. In conclusion, these findings were evidence of a positive and moderately strong correlation between perceptions of transactional distance and online student engagement among the sampled STEM students in two-year community colleges. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]