Abstract: With the development and spread of social media sites, individuals must learn how to maximise their positive impact while minimising their negative effects. In this study, the relationship between social media and self-esteem has been explored, in addition to personality traits and how they differ in time spent on social media and self-esteem. The objective of this study is to determine whether social media affects individuals' mental health and self-esteem. This aim has been accomplished by meeting the following objectives: Determine whether social media affects the level of self-esteem among young adults, compare different personality traits, and assess the time spent on social media. Also, consider whether people with different personalities differ in their self-esteem. The participants of this study were approximately 385 male and female young adults aged 18 to 26 in Saudi Arabia. To measure these variables, the Big Five factors of personality by John Donahue and Kent, the self-esteem scale by Hudson, and the social media scale have all been used in the Arabic versions. The results show that social media and self-esteem are positively correlated with a large effect, and personality traits have a different level of association with social media use and with self-esteem.