The design of manual toys for autistic children requires careful attention to sensory-ergonomic parameters to support engagement, self-regulation, and developmental growth. This review systematically synthesizes evidence published between 2019 and 2025, drawing on PRISMA 2020 guidelines, to evaluate how tactile, visual, and auditory factors can be effectively embedded in toy design. Findings highlight that autistic children often present with co-occurring sensory differences, including hyper- and hyporeactivity, necessitating toys that are customizable and predictable. Tactile design principles emphasize the importance of texture, deep pressure, and material durability, while visual design benefits from muted colors, clarity of form, and graded challenge to reduce aversion and promote calm engagement. In the auditory domain, toys that avoid sudden, high-intensity sounds and instead provide controlled and user-adjustable inputs are shown to better support communication and play. Beyond sensory features, successful manual toys incorporate predictability, simplicity, and user control, enabling them to function not only as play objects but also as therapeutic tools that foster social interaction, playfulness, and communication. Despite progress, current research faces limitations related to sample sizes, specificity of sensory parameters, and implementation contexts. Future work must emphasize rigorous validation, greater personalization, and structured integration into real-world settings. This review contributes to advancing a sensory-ergonomic framework for manual toy design, providing an evidence base to inform both therapeutic and developmental applications.