The need to enhance students' learning outcomes has become integral in secondary schools in developing countries due to increased students enrollment. Research has shown that the strategies utilized in teaching secondary school students have significant influence on their learning outcomes. At present in Nigeria, public secondary schools have not been deploying learning technologies to teach students despite the surge in enrollment. This study, therefore, determined the effects of computer-aided and blended teaching strategies on students' achievement in civic education concepts in mountain learning ecologies. The study adopted the pretest-posttest, control group, quasi-experimental design using 3 × 2 × 3 factorial matrix. Seventy-eight students from six intact classes in secondary schools in Ondo State were selected for the study and randomly assigned to experimental and control groups. Five instruments used were: Students' Knowledge of Civic Education Test (r = 0.78), Academic Ability Test (r = 0.72), Online and Blended Teaching Instructional Guides for experimental groups, Conventional Lecture Method Guide for the control group and Teaching Strategies Evaluation Sheet. One hypothesis was tested at 0.05 level of significance. Data was subjected to Analysis of Covariance, Estimated Marginal Means, and Scheffe's Pairwise Comparison. There was a significant effect of treatment on students' achievement in Civic Education concepts (F[subscript (2; 61)] = 4.93, p < 0.05; ?[superscript 2] = 0.14). The students exposed to Computer-aided teaching programme had higher adjusted achievement mean score (x-bar = 27.86), than the blended instructional strategy group (x-bar = 23.06), and the control group (x-bar = 18.69). It was, therefore, recommended that teachers in secondary schools in mountainous locations should explore the benefits of teaching with Information and Communication Technology based strategies in civic education classrooms.