Offsite construction (OSC) is promoted as a strategy that aims to boost competition, increase productivity, and remove market barriers, driving the construction sector towards innovation. Yet, the procurement strategy of OSC has not evolved, and it is challenging to scope the procurement strategy without a unified definition for OSC. Hence, this chapter aims to define OSC as a part of an extensive study which looks at the procurement strategies of projects using OSC. A systematic literature review was carried out using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A sum of 42 literature sources were screened from four databases. A descriptive and qualitative analysis was conducted. The literature sources span from 2010–2022 based on their year of publication, and more than 75% of the studies are from Oceania, Europe, and Asia combined together. The interpretations of OSC were analysed against the objectives of the selected studies, and a framework was developed to construct a definition. The framework consists of essential attributes of the definition of OSC, such as integrated manufacturing and design, a controlled factory environment, emphasis on the supply chain, and standardised and repeatable products. Moreover, the framework highlights potential attributes for enhancing the contextual definition, material selection, product customisation, logistic considerations, and stakeholder engagement, to name a few. The review demonstrates that procurement strategy is also a potential attribute that can enhance the contextual definition. The researchers can then extend this study to explore existing and novel procurement options that adhere to the definition of offsite construction.