Polyetheretherketone (PEEK), a member of the polyaryletherketone family, has gained increasing attention in dentistry because of its favorable biomechanical properties, low density, radiolucency, chemical stability, and biocompatibility. Compared with metallic materials, PEEK and especially fiber-reinforced PEEK exhibit a lower elastic modulus, which may contribute to more favorable stress distribution in selected implant and prosthetic applications. PEEK has been investigated for dental implants, implant abutments, fixed and removable prostheses, post-core systems, maxillofacial prostheses, periodontal splints, occlusal splints, and orthodontic appliances. However, pure PEEK is biologically inert and has low surface energy, which may limit osseointegration and adhesive bonding. To overcome these limitations, surface treatments such as plasma activation, sulfonation, and hydroxyapatite coating, as well as bulk modifications including ceramic or fiber reinforcement, have been proposed. This review summarizes the current dental applications of PEEK, its main advantages and limitations, and future perspectives for clinical use. Although PEEK is a promising dental biomaterial, most applications still require further long-term clinical validation before routine use can be recommended.