Citrus fruit tree has great importance in Brazil. Despite having many commercial cultivars, the lemon crop in Brazil is basically from “Tahiti” cultivar and there is a lack of studies about the characterization and assay of genetic diversity of sweet lemon (Citrus limetta) fruits. Therefore, this work aimed to characterize and evaluate the genetic diversity from nine stock plants produced in Porto Nacional-TO. Fruits in fully physiologic ripening were harvested and evaluated for weight, length, diameter, juice yield, soluble solids content, and color of peel and pulp. The experimental design was completely randomized with 9 treatments (stock plants) and five replications. For the characterization, the data were subjected to Tukey’s test and similarity measure and clustering of the stock plants were performed by Tocher’s method and UPGMA dendrogram. Weight, length, and diameter of all stock plants have not differed from each other. The coordinate b* indicated that stock plant 1 had fruits with peel and pulp clear when compared to the yellow color of the other stock plants. There was genetic diversity between the assessed stock plants and three groups were created, which stock plant 1 and 2 were the most divergent and compose group 3, according to Tocher’s method. The features contributed similarly to total variation.