Public sector purchasing processes are gaining increasing prominence as a demand-side innovation tool for addressing national sustainability challenges. Accordingly, there has been growing research attention to this topic. Prior studies suggest three key rationales that underlie the use of public sector procurement to drive innovation: (i) the buyer-user rationale (for creating new needs); (ii) the market/system failure rationale (for improving suppliers' capacity to innovate); and (iii) the public services rationale (for improving public services). However, operational activities at the upstream supply chain affecting the sustainable innovation capacities of supplier firms appear to be under-researched in the public procurement for innovation (PPI) scholarship, despite knowledge about innovation capacity being critical to successfully implementing PPI. This paper adopts a systematic literature review approach to synthesise existing fragmented literature on sustainability-oriented PPI, focusing on supplier perspectives. Findings from a synthesis of 41 relevant articles suggest, among others conditions, that a procurement framework that maintains a good balance of competition and innovation, builds buyer-supplier relationship and urges strong supply networks, maintains a stable political commitment, offers security for niche markets with effective innovation risk management culture would enhance suppliers' sustainability capacity and propensity to innovate. This paper contributes to the PPI literature and the literature on determinants of sustainable innovation systems from supplier firms' sustainability lens.