The aim of this study was to identify the common personality characteristics of the juvenile delinquents in Oman and to know the range of differences these characteristics in the study variables. In addition, it was to know differences in personality characteristics between the juvenile delinquents and non- juvenile delinquents in the Sultanate of Oman. The samples of this study were all the juvenile delinquents who are in the Central Prison in Smail. They were 40 and their ages varied between (12-17) years old. Moreover, another sample was taken from three different schools in Muscat. The number of the students were 100 and their ages were between (12-17). Description protocol has been applied to achieve the outcomes of this study. Also, it applied the (NEO-FFI-S) was done by Costa and McCrea, 1992. The answer of the study's Questions were done by using some different tests which included Average, Standard Deviation, T-Test, One Way ANOVA. The results showed that the most common characteristics of Juvenile delinquents in Oman were Neuroticism and Openness. In the second place, came the Agreeableness and Extraversion. On the other hand, the result showed that the Conscientiousness is not one of their characteristics. Furthermore, the results showed that there was a statistical difference in the personality characteristics in the all study variables. Moreover, they showed a statistical difference in the five major characteristics between the juvenile delinquents and non-juvenile delinquents.