Social networking sites (SNS) refer to a type of online social platform that users use to create social networks or social connections with others who possess similar type of interests, backgrounds, hobbies, or real- world connections. The users (students, teachers etc) exchange thoughts, teaching-learning materials, digital images, videos, and postings with others and tell them about online or offline activities and events, in their social network. These individuals use websites, which may include Instagram, Twitter, Facebook, YouTube etc. However, excessive use of such websites may cause people to develop a social networking addiction, which is commonly known as online addiction. Excessive use of social networking sites evidently, can raise the risk of major mental health conditions such as depression, anxiety, tension, stress, mental disease, behavioral disorders, and a general lack of happiness with life among users. After collecting the review of literature from different database sources, this study aims to achieve the following objectives:1) To study the social networking sites as a new online addiction. 2) To know the effects of SNSs on mental health. The reviewers used the Exclusion and Inclusion criteria (PRISMA) to achieve the set objectives. The findings of the different studies indicate that Social Networking Addicts have more social anxiety, higher rates of depression, poor body image, and reduced levels of empathy and compassion towards others than Non-SNSs Addicts. The results also indicate that there is a significant difference between males and females in several areas of mental health, such as perception of reality, personality integration, positive self-evaluation, and group oriented attitude. This study is purely based on secondary data. The data is collected from different sources like Google, research papers, articles, Google scholar and from different journals.