Smart manufacturing, Industry 4.0 and Smart Factory are phenomena regarded as a key necessity for Small, Medium and Micro Businesses (SMMEs) worldwide. Even though these 4th Industrial Revolution (4IR) phenomena are generally used interchangeably, this paper sought to identify how SMME readiness for smart manufacturing has been investigated through a systematic review. The systematic review was conducted through the lens of Nooteboom, and Tornatzky and Klein’s research on technological innovation in SMMEs based on Rogers’ diffusion of innovations theory. The findings reveal that there is little to no research on smart manufacturing in relation to SMMEs in low-income countries particularly the African continent. The results also show that smart manufacturing is still an emergent phenomenon with disparate definitional challenges. These definitional challenges make the adoption of smart manufacturing innovations a challenge in resource-constrained contexts; but similarly present an opportunity for new definitions and theories in such contexts. The little research often treats SMMEs homogenously and as such misses their important heterogeneous (sector or industry specific) nature. Few research studies investigate SMME awareness (adequate knowledge) or make explicit the benefits (relative advantage) of smart manufacturing. Even fewer studies are explicit on the smart manufacturing technologies that are relevant for different SMME sectors. Smart manufacturing is identified as incompatible with SMME characteristics, that is SMMEs lack expertise/skills to comprehend the complexity of smart manufacturing, and also lack financial and human resources to implement smart manufacturing. Given that awareness, relative advantage, complexity and compatibility are critical barriers for SMME smart manufacturing readiness/adoption, there is a critical need for research to focus on these factors in particular for the context of resource constrained low-income country environments.