Narbon vetch (Vicia narbonensis L.) is a promising forage legume with good resistance to cold and drought. The assessment of genetic diversity of Narbon vetch is an essential component in germplasm management. In this study, we analysed the genetic diversity of 13 local and introduced Narbon vetch accessions from three continents using 27 morphological traits and 13 simple sequence repeat (SSR) markers. Significant differences among accessions for morphological and phenological traits were observed. The SSR markers showed a total of 126 alleles with a mean number of two alleles per locus. Polymorphic information content values were in the range of 0.772–0.915 with an average of 0.858. A high level of diversity (Nei’s genetic differentiation index of 59) was observed among accessions. Analysis of genetic distances separated the studied accessions into three groups based on both morphological and SSR markers. Cluster analysis of the SSR markers separated the accessions into three groups according to geographical origin. The Tunisian populations shared the same morphological traits but differed genetically from each other and were similar to those from Lebanon. A significant correlation was detected between morphological traits and SSR markers. The results suggested that SSR markers can be used to efficiently distinguish Narbon vetch accessions and estimate their genetic diversity.