This article presents the findings of a systematic review of perceived usability of educational technology systems. The research was conducted after studying, organizing, and analyzing the results of 104 research papers evaluating perceived usability of educational technologies using the System Usability Scale (SUS). The results were organized on the basis of (a) the usability score obtained when using the SUS, (b) the type of educational technology used, (c) the subject being learned, (d) the level of education, (e) the type of participant, (f) the age, and (g) the number of participants in each survey. Statistical analysis in all surveys (N = 170) demonstrated a good level of usability but with some issues (M = 70.09, SD = 12.98). The categories of Internet platforms (M = 66.25, SD = 12.42), university websites (M = 63.82, SD = 16.52) and affective tutoring systems (ATS) (M = 68.87, SD = 7.30) seem to have a good usability level according to SUS, preceded by mobile applications (M = 73.62, SD = 13.49) and multimedia (M = 76.43, SD = 9.45). Moreover, SUS scores were not found to be significantly related with participants' age (r = 0.017, p = 0.931, ns), stage of education (p = 0.539, ns), or the type of participants (p = 0.639, ns). Furthermore, the subject being learned (p = 0.038, s) and the number of participants in each survey (r = -0.259, p = 0.001, s) seem to relate to the obtained SUS scores. ? slight, statistically insignificant improvement is noted in the perceived usability over the years (p = 0.182, ns). The findings of this review will serve as a useful reference guide for educational technology designers, practitioners, and teachers.