Since the discovery of bone marrow mesenchymal stem cells (BMMSCs), many researchers have focused their attention on new sources of mesenchymal stem cells (MSCs). Consequently, MSCs that display self-renewal capacity, multidifferentiation potential and immunomodulatory properties have been isolated from human oral tissues, including tooth, periodontal ligament, and gingiva. Oral MSCs involve dental pulp stem cells (DPSCs), stem cells from exfoliated deciduous teeth (SHED), periodontal ligament stem cells (PDLSCs), dental follicle stem cells (DFCs), stem cells from apical papilla (SCAP) and gingival stem cells (GMSCs). Current research on oral stem cells is expanding at an unprecedented rate. That being the case, a plethora of in vitro differentiation assays, immunodeficient animal transplantations and preclinical trials have demonstrated that these cells exhibit strong potential for both regenerative dentistry and medicine. Oral MSCs have proved their capability to repair cornea, dental pulp, periodontal, bone, cartilage, tendon, neural, muscle and endothelial tissues without neoplasm formation as well as to treat inflammatory diseases and immune disorders. This article describes the current understanding of oral MSCs and their prospective applications in cell-based therapy, tissue engineering and regenerative medicine. Special attention is placed on GMSCs as they are easily accessible and may be obtained in a convenient and minimally invasive way.