Social prescribing (SP) is a way of addressing the “nonmedical” needs (e.g. loneliness, debt, and housing problems) that can affect people’s health and well-being. The National Health Service (NHS) in England implemented SP link workers (LWs) in General Practitioner (GP) practices through its Long-Term Plan in 2019. While SP LWs facilitate the connection between patients and social prescriptions, GPs are often the ones responsible for the first stage in the SP pathway: identifying the need for SP and then referring the patient to a LW. While single studies have examined the perspectives and experiences of GPs with SP, they have not been reviewed and synthesized previously. Therefore, a thematic synthesis of qualitative studies was conducted to address the question “What are UK GP experiences with and perceptions of SP?” Seven databases and Google Scholar were systematically searched for references: Medline, PsycInfo, CINAHL, Embase, Scopus, ASSIA, HMIC, and ProQuest. Quality assessment was undertaken using the CASP tool. From 265 references, 57 potential papers were read in full, and 12 were included in the review. An overarching theme was identified as “the GP as a salesperson for SP.” It was informed by the following three analytical themes: “belief in the product,” “ability to sell the product,” and “navigating market constraints.” Data showed that GP engagement in SP is multifaceted, involving individual attitudes, medical culture, and systemic contexts. The review highlights the critical role of GPs as gatekeepers in SP, influenced by both intrinsic and extrinsic factors. To enhance SP’s implementation, addressing these factors through education, policy, and community support is essential.