: Self-esteem is affected by many factors and it is instrumental in numerous broader psychosocial outcomes for children and adolescents, with low self-esteem having negative impacts. The objective of the paper is to measure self-esteem and examine its predictors among school-aged students in Jordan. The methods of the paper is Ten schools using simple random sample were included. Students answered the Arabic Version of Rosenberg Self-Esteem Scale (ARSES) and Demographic Data and Characteristics Checklist. Almost half of participants were males, with a mean age of 14.38 years, mean weight of 57.39 kg, mean height of 164.19 cm, mean number of siblings of 1.41, and mean self-esteem ARSES score of 23.07. Significantly higher self-esteem was reported by male students, and students studying the international (as opposed to national) program of study. Regression model showed that increased number of siblings, increased height, and increased age predicted increased self-esteem, while increased weight predicted decreased self-esteem. Being a male student and studying at international program predicted an increase in students’ self-esteem. Academic performance did not predict a change in self-esteem. Conclusion: School students at this age were vulnerable to low self-esteem, and their weight was found to be strongest predictor of self-esteem. Therefore, schools should emphasize physical activity, healthy eating habits, and weight management awareness for their students..