<p>Test anxiety is a widespread and serious concern among school-age students that is associated with lower academic achievement and other negative psychological outcomes. This study evaluated the efficacy of a multimodal universal classroom-based test anxiety intervention program for secondary school students that combined cognitive and behavioral techniques together with study and test-taking skills training. The sample for analysis included 194 Grades 8 and 9 students across three secondary schools in Singapore. Using a cluster randomized controlled trial, randomization occurred at the class level to the experimental or waitlist control group. Participants completed the outcome measures twice at pre- and posttest, before and after the experimental group had received the intervention. Intervention outcomes were extended beyond reduction in test anxiety levels to include improvements in students’ overall psychological wellbeing and greater utilization of test-taking coping skills. The three student outcomes were first combined into a composite variable to examine the overall effect of intervention before each outcome was evaluated individually. Results indicated that after controlling for pretest scores on the three outcome measures, intervention had a significant positive effect on the composite variable and for each individual outcome for students in the experimental group compared to the waitlist control group, at posttest. Findings support the efficacy of universal classroom-based multimodal interventions in reducing students’ test anxiety and enhancing their overall psychological wellbeing and test-taking coping skills.</p>