Background: More students state that they are exposed to bullying and the mental illness among adolescents increases. Previous research states that there is a connection between bullying and reduced well-being, where social factors have been emphasized as risk and protective factors for both bullying and well-being. However, it is not well studied which social factors who has the biggest impact on well-being based on positive and negative aspects. Social capital was used as a theoretical frame to explain the social factors’ influence on adolescent’s well-being. Aim: The aim of the study was to study bullying and which social factors who has the biggest impact on well-being among adolescents in the County Council of Västmanland. Method: Based on the Survey of Adolescent Life in Västmanland 2012, a quantitative approach was applied with a cross-sectional design. A total of 4226 students from 9th grade of compulsory school and the 2nd year of upper secondary school in the County Council of Västmanland were included. Descriptive analyzes and multiple linear regression analyzes were performed. Results: Positive influences showed greater variety in well-being and future optimism than negative influences. Negative experiences had a greater influence than positive experiences while physical, verbal and psychological bullying had a low influence. Conclusion: A majority of students had not experienced any form of bullying where physical bullying was least common while mental bullying was most common. Students’ well-being was highly rated, boys rated their well-being as better than girls. School well-being and negative experiences had the greatest influence in well-being and future optimism.