Both periodontal disease and atherosclerosis are chronic disorders with an inflammatory substrate that leads to alteration of the host’s immune response. In PD, inflammation is responsible for bone tissue destruction, while in atherosclerosis, it leads to atheromatous plaque formation. These modifications result from the action of pro-inflammatory cytokines that are secreted both locally at gingival or coronary sites, and systemically. Recently, it was observed that in patients with PD or with cardiovascular disease, COVID-19 infection is prone to be more severe. While the association between PD, inflammation and cardiovascular disease is well-known, the impact of COVID-19-related inflammation on the systemic complications of these conditions has not been established yet. The purpose of this review is to bring light upon the latest advances in understanding the link between periodontal–cardiovascular diseases and COVID-19 infection.