Disseminated herpes zoster (DHZ), resulting from the reactivation of the varicella-zoster virus (VZV), typically occurs in immunocompromised persons. To date, only four cases of DHZ following mRNA, viral vector, or inactivated COVID-19 vaccinations have been reported in immunocompetent patients. Herein, we present the first case of DHZ following the protein subunit COVID-19 vaccination (case 1, 64 years old) and a case of DHZ following mRNA COVID-19 vaccination (case 2, 67 years old) in elderly, immunocompetent male patients. Both cases were generally healthy, without a remarkable underlying disease and without a history of immunosuppressant use. Case 1 developed DHZ (left C3–5 predominant) 1 month after receiving the third dose of the SARS-CoV-2 spike protein vaccine (MVC-COV1901). Case 2 developed DHZ (right V1–3 predominant) 7 days after receiving the second dose of the mRNA-1273 SARS-CoV-2 vaccine. Through skin examination, Tzanck smears, and dermoscopy, the diagnosis of COVID-19 vaccination-related DHZ was established in both cases. Oral famciclovir (250 mg, three times/day for 7 days) was administered, and both cases achieved total remission of skin lesions without visceral involvement or severe post-herpetic neuralgia. Our cases demonstrate that DHZ, as a rare cutaneous adverse event in immunocompetent patients, can be secondary not only to mRNA COVID-19 vaccination but also to the protein subunit COVID-19 vaccination. It is speculated that the spike protein of SARS-CoV-2 could be the common trigger for the reactivation of VZV among different types of vaccinations.