Achilles tendinopathy (AT) is common, particularly in runners. High-volume injections (HVIs) may be beneficial in the management of AT compared to other conservative management options, including exercise regimens, platelet-rich plasma (PRP) injections, and extracorporeal shockwave therapy. The published research on the effectiveness of HVI in the treatment of AT was evaluated in this systematic review. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed when conducting this systematic review. The electronic databases PubMed, Embase, Cochrane, Web of Science, CINAHL, and OVID were thoroughly searched, from inception to 13 September 2023, for articles assessing HVI for AT. A total of 10 studies with 460 participants met the inclusion criteria. HVI typically consisted of saline, local anaesthetic, and corticosteroids. HVI combined with corticosteroids demonstrated immediate and long-term improvements in ankle function. Compared to HVI without corticosteroids, HVI with corticosteroids exhibited greater, early improvements in pain and function, with no significant differences at later follow-up points. Significant reductions in tendon thickness and neovascularity were also found with HVI treatment over time. No adverse events were reported with HVI, despite the use of corticosteroids. HVI is an effective and safe modality, particularly in the short term, to significantly reduce pain and discomfort in the Achilles tendon, especially when supplemented with corticosteroids. More robust randomized controlled trials, with longer-term follow-ups and homogeneity, are needed to fully establish its efficacy for AT.