Glioblastoma (GB) is a highly aggressive brain tumor with a very poor prognosis. Treatment usually consists of surgery, followed by radiotherapy and chemotherapy, but the prognosis remains poor due to its resistance to therapies and a high recurrence rate. Multiple studies have reported the presence of human cytomegalovirus (HCMV) proteins and/or nucleic acids in GB tissues, suggesting its possible implication. These findings have led to the hypothesis that HCMV may contribute to tumor progression, immune evasion, angiogenesis, and resistance to therapy. Clinical trials using anti-HCMV therapies have shown promising preliminary results, indicating a potential therapeutic benefit. This review aims to provide a comprehensive overview of the current evidence linking HCMV to GB and the therapeutic implications. A deeper understanding of this complex interaction could unveil novel strategies for GB treatment.