Durum wheat (Triticum turgidumL.) is the 10thmost cultivated crop and is a vitalfood source for human consumption. Genetic diversity in durum wheat is still anunexplored subject, and gene banks are filled with accessions waiting to be screened.Here, four different groups of durum wheat, Turkish and foreign cultivars, and in situand ex situ landraces were evaluated for population structure and genetic diversity.A collection of 129 durum wheat accessions were genotyped, with a total of 6,357markers (SilicoDArT, SNP [single-nucleotide polymorphism], and simple sequencerepeats [SSRs]). The highest mean allele number per marker (1.562) was obtainedwith SNP markers in ex situ landraces; the lowest mean allele number per marker(0.788) was obtained with SSR markers in the foreign cultivars. The minimum per-centage of polymorphic loci was 38.70% observed with SSR markers in foreign culti-vars; the maximum was 76.20% in SilicoDArT markers in ex situ landraces. Accord-ing to Neighbor-Joining analyses, the studied collection was divided into groups ofcultivars and landraces, with some level of admixtures. Structure and principal coor-dinate analysis obtained distinct clusters for ex situ landraces and foreign cultivars,supported by Neighbor-Joining analysis. A significant level of intergroup and intra-group variation was observed, and Turkish ex situ landraces were found as the mostdiverse and distinct group in the collection. Turkish landraces may be a promisingsource of novel allelic diversity that can be used in durum wheat breeding worldwide.Durum wheat (Triticum turgidumL.) is the 10thmost cultivated crop and is a vital food source for human consumption. Genetic diversity in durum wheat is still an unexplored subject, and gene banks are filled with accessions waiting to be screened. Here, four different groups of durum wheat, Turkish and foreign cultivars, and in situ and ex situ landraces were evaluated for population structure and genetic diversity. A collection of 129 durum wheat accessions were genotyped, with a total of 6,357markers (SilicoDArT, SNP [single-nucleotide polymorphism], and simple sequence repeats [SSRs]). The highest mean allele number per marker (1.562) was obtained with SNP markers in ex situ landraces; the lowest mean allele number per marker(0.788) was obtained with SSR markers in the foreign cultivars. The minimum percentage of polymorphic loci was 38.70% observed with SSR markers in foreign cultivars; the maximum was 76.20% in SilicoDArT markers in ex situ landraces. According to Neighbor-Joining analyses, the studied collection was divided into groups of cultivars and landraces, with some level of admixtures. Structure and principal coordinate analysis obtained distinct clusters for ex-situ landraces and foreign cultivars, supported by Neighbor-Joining analysis. A significant level of intergroup and intra-group variation was observed, and Turkish ex-situ landraces were found as the most diverse and distinct group in the collection. Turkish landraces may be a promising source of novel allelic diversity that can be used in durum wheat breeding worldwide.