Garlic is one of the most widespread and ancient medicinal plants. Its health benefits are due to its chemical components, and among these is carbohydrate, whose characteristics have been so far little investigated. The aim of this study is to typify the various components of carbohydrate (starch, individual sugars, fructans, and total dietary fibre) in four commonly consumed “Italian local landraces”: Bianco Piacentino, Rosso di Castelliri, Rosso di Sulmona, Rosso di Proceno, which are grown in two different geographical areas—Viterbo and Alvito—under the same agronomic conditions. This study will also evaluate how genotype and the cultivation area can affect the profile of the carbohydrate components of these landrace strains. Regarding unavailable carbohydrates, all of the varieties showed appreciable contents of fructans, the most representative component, which ranged from 45.8 to 54.4 g/100 g d.w. In contrast, total dietary fibre values varied from 9.1 to 13.1 g/100 g d.w. in Rosso di Castelliri and Bianco Piacentino, respectively, which are both grown in Viterbo. As for starch, only some traces were found, while the amount of total sugars ranged between 2.12 and 3.27 g/100 g d.w., with higher levels of sucrose. Our findings could provide important information that may be adopted to enhance and promote the quality of some local Italian garlic landraces through highlighting the influence that the cultivar and the environmental conditions can have on carbohydrates components.