Introduction Autistic students may experience difficulty performing classroom tasks due to atypical sensory processing and inefficient use of higher-order cognitive strategies. Limited research has investigated the influence of in-class sensory activities to enhance the thinking strategies required for task performance. This study evaluated a classroom-based sensory activity schedule and its impact on cognitive strategy use. Methods A quasi-experimental, non-equivalent groups design was used. Students (n = 30, mean age 7.4 years) with atypical sensory processing negatively impacting classroom performance, and their teachers (n = 23), from six autism-specific schools were grouped into intervention (Sensory Activity Schedule and usual teaching) and control (usual teaching only) groups. Students' cognitive strategy use during the performance of classroom tasks was evaluated at baseline and post-intervention using Perceive, Recall, Plan, Perform Stage Two Cognitive Task Analysis. Results Statistical analysis (Mann-Whitney U test) indicated that students who received the Sensory Activity Schedule intervention improved significantly more than control group students in overall cognitive strategy use (Z = -2.32, p = 0.02), and with strategy items involving attention and sensory perception (perceive, Z = -2.26, p = 0.02), and planning and organisation (Plan, Z = -.254, p = 0.01). Conclusion The Sensory Activity Schedule may enhance autistic students' capacity to apply cognitive strategies more effectively during performance of classroom tasks.