In the context of global efforts to enhance manufacturing sustainability, the adoption of digital technologies, particularly Artificial Intelligence and smart systems, is becoming increasingly prevalent under the Industry 4.0 paradigm. However, the majority of extant reviews neglect to examine the particular, quantifiable consequences of such technologies on environmental and social sustainability. This systematic literature review addresses this gap by isolating and synthesizing the direct positive contributions of AI and smart technologies within manufacturing contexts. The PRISMA framework was used to select and analyze a rigorous sample of over 200 articles. The study provides a structured overview and original classification of sustainability outcomes, supporting more targeted academic and industrial strategies.