Background: The transition from high school to post-secondary education and work is difficult for adolescents on the autism spectrum. Transition planning can be an effective way of supporting adolescents on the autism spectrum to prepare for leaving school and to succeed in obtaining employment; however, there is a need for an autism-specific transition planning program with proven effectiveness. This paper describes a trial protocol for evaluating the Better OutcOmes amp; Successful Transitions for Autism (BOOST-A (TM)); an online interactive program that empowers adolescents on the autism spectrum to plan their transition from school to further study, training, or employment. Methods: The trial will involve adolescents on the autism spectrum in high school and their parents, who will be alternately assigned to a control group (regular practice) or an intervention group (using the BOOST-A (TM)). The BOOST-A (TM) was developed using the PRECEDE-PROCEED model, and is based on the self-determination model, and the strengths-and technology-based approaches. It involves participants completing a series of online modules. The primary outcome will be self-determination, because high self-determination has been linked to successful transition to employment among adolescents on the autism spectrum. Secondary outcomes will include domain-specific self-determination, career planning and exploration, quality of life, and environmental support. Data will be obtained from questionnaires completed by the adolescent on the autism spectrum and their parent/s. Data collection will take place at baseline (Time point 1) and 12 months later (Time point 2). Discussion and conclusions: This trial will provide evidence of the effectiveness of the BOOST-A T to assist adolescents on the autism spectrum to successfully transition from school.