Shape Memory Alloys (SMAs) have emerged as a promising actuation technology for wearable rehabilitation robots due to their unique properties, including the shape memory effect, high actuation stress, pseudoelasticity, and three-dimensional actuation. With a significantly higher Young’s modulus than biological tissues, SMAs enable efficient and responsive interaction with the human body, making them well suited for musculoskeletal rehabilitation applications. This paper provides a comprehensive review of SMA-based wearable devices for both upper- and lower-limb rehabilitation. It explores their configurations, actuation mechanisms, associated challenges, and optimization strategies to enhance performance. By discussing recent advancements, this review aims to inform researchers and engineers on the development of sustainable, effective, and patient-centric wearable rehabilitation robots.