A plethora of systemic manifestations of COVID-19 and adverse reactions to COVID-19 vaccines have been described in pediatric subjects. Therefore, the present systematic review primarily aimed to assess the prevalence and macro-microscopic features of oral lesions following SARS-CoV-2 infection, grading primary oral lesions based on COVID-19 forms, in pediatric subjects. The secondary aim was to evaluate the epidemiology, clinical appearance, and histopathology of oral lesions following the WHO Emergency Use Listing approved and EMA authorized vaccines, in relation to cases and vaccine characteristics. The study protocol was compliant with the PRISMA statement and registered on PROSPERO (CRD42022351821). Case reports, case series, and observational studies were electronically searched till 27 July 2022, on MEDLINE/PubMed, Scopus, and Cochrane library databases, and the PROSPERO register. Data from nine studies describing oral lesions following viral infection and two records reporting oral lesions following vaccine administration, evaluated through the ROBINS-I tool for quality, were independently extracted and qualitatively synthesized, resulting in scarce, jeopardized, and incomplete findings. Since most of the rare lesions recorded were a part of broad-spectrum systemic disorders and syndromes and, thus. undetailed or nonspecific, further studies should assess oral lesions following SARS-CoV-2 infection and vaccination in pediatric subjects, considering novel viral variants and newly developing vaccines.