From 2009 to 2014 a nationwide effort was made to document, collect, conserve, and characterize wheat landraces grown by Turkish farmers. Spike samples were collected from more than 1600 farmers from 59 provinces, planted as single-spike progenies, and classified into species, subspecies, and botanical varieties (or morphotypes). Altogether, 95 morphotypes were identified representing three species and six subspecies: einkorn wheat (Triticum monococcum L.), emmer wheat [T. turgidum subsp. dicoccon (Schrank) Thell.], cone wheat (T. turgidum subsp. turgidum), durum wheat [T. turgidum subsp. durum (Desf.) Husn.], bread wheat (T. aestivum L. subsp. aestivum), and club wheat [T. aestivum subsp. compactum (Host) Mackey]. Compared with a nationwide survey in 1920, these findings represent a loss of 50 to 70% of the diversity found in 1920, though in four provinces, little if any loss occurred. Based on the Shannon diversity index (H¢) and number of morphotypes, the highest diversity for bread wheat was observed in Manisa, Konya, Iğdır, Diyarbakır, and Tokat provinces and for durum wheat in Adana, Diyarbakır, and Hatay provinces. Socioeconomic data indicated that landrace farmers are found mostly in remote mountainous subsistence communities with very little grain trade, small areas planted to wheat, and relatively simple production technologies. The key reasons famers continue to grow landraces are their grain qualities and adaptation to abiotic stresses. In situ conservation should be targeted at provinces with the highest morphotype diversity, with the rarest landraces, and with the highest share of farmers growing landraces.