Background: People with intellectual disabilities may find difficulties in their school-to-work transition. The current study aimed to determine which factors have been investigated and which are relevant to this transition process. Method: A systematic review was undertaken using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and included studies published between 2011 and 2023 on initiatives that facilitate the school-to-work transition. Results: Four broad types of interventions were encountered: career and vocational guidance, training for the development of key competencies, school-based transition programs, and work-based learning. Most studies were quantitative and included key competencies in training activities that focus on specific skills that facilitate the school-to-work transition process. Conclusions: In order to enable the continuity of processes related to school-to-work transition and to improve inclusive employment and social skills for people with intellectual disabilities, there is a clear need to collect initiatives across countries.