The oral cavity may play a role as a reservoir and in the transmission and colonization of Helicobacter pylori. The route of transmission for H. pylori is not fully understood. The prevalence of this pathogen varies globally, affecting half of the world’s population, predominantly in developing countries. Here, we review the prevalence of H. pylori in the oral cavity, the characteristics that facilitate its colonization and dynamics in the oral microbiome, the heterogeneity and diversity of virulence of among strains, and noninvasive techniques for H. pylori detection in oral samples. The prevalence of H. pylori in the oral cavity varies greatly, being influenced by the characteristics of the population, regions where samples are collected in the oral cavity, and variations in detection methods. Although there is no direct association between the presence of H. pylori in oral samples and stomach infection, positive cases for gastric H. pylori frequently exhibit a higher prevalence of the bacterium in the oral cavity, suggesting that the stomach may not be the sole reservoir of H. pylori. In the oral cavity, H. pylori can cause microbiome imbalance and remodeling of the oral ecosystem. Detection of H. pylori in the oral cavity by a noninvasive method may provide a more accessible diagnostic tool as well as help prevent transmission and gastric re-colonization. Further research into this bacterium in the oral cavity will offer insights into the treatment of H. pylori infection, potentially developing new clinical approaches.