While most supernumerary teeth are idiopathic, they can be associated with a number of Mendelian syndromes. However, this can also be a coincidental finding, since supernumerary teeth occur in 6% or more of the normal population. To better define this relationship, we analyzed the evidence for specific associations. We excluded conditions with a single affected patient reported, supernumerary teeth adjacent to clefts or other forms of alveolar disruption (as secondary rather than primary findings), and natal teeth, which can involve premature eruption of a normal tooth. Since, the cause of supernumerary teeth shows considerable heterogeneity, certain findings are less likely to be coincidental, such as five or more supernumerary teeth in a single patient, or locations outside of the premaxilla. We found only eight genetic syndromes with strong evidence for an association: cleidocranial dysplasia; familial adenomatous polyposis; trichorhinophalangeal syndrome, type I; Rubinstein–Taybi syndrome; Nance–Horan syndrome; Opitz BBB/G syndrome; oculofaciocardiodental syndrome; and autosomal dominant Robinow syndrome. There is also suggestive evidence of an association with two uncommon disorders, Kreiborg–Pakistani syndrome (craniosynostosis and dental anomalies), and insulin‐resistant diabetes mellitus with acanthosisnigricans. An association of a Mendelian disorder with a low frequency manifestation of supernumerary teeth is difficult to exclude without large numbers, but several commonly cited syndromes lacked evidence for clear association, including Hallermann–Streiff syndrome, Fabry disease, Ehlers–Danlos syndrome, Apert and Crouzon syndromes, Zimmermann–Laband syndrome, and Ellis–van Creveld syndrome. © 2016 Wiley Periodicals, Inc.