This study aimed to analyze patterns and predictors of secondhand smoke (SHS) exposure among adolescents (12–16 years old) in Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and the United Arab Emirates. Nationally representative data from the most recent Global Youth Tobacco Survey in each country were analyzed (N = 17,220). SHS exposure at home, in public places, and at school was assessed. Descriptive statistics summarized exposure prevalence overall and by sex. Multivariable logistic regression examined factors associated with each SHS exposure’s outcome. The results showed that SHS exposure was high overall, with exposure at home and school ranging from 12.7 to 20.7%, respectively, in Oman to 39.4% and 36.7%, respectively, in Kuwait. Almost half of the adolescents reported exposure to SHS in public places, with a prevalence of 40.8% in Saudi Arabia to 65.9% in Kuwait. The prevalence of exposure varied between countries, with the highest rates occurring in Kuwait. Girls had higher exposure at home, while boys had higher exposure in public and at school. Factors associated with higher exposure included parental smoking, friend smoking, and tobacco advertising. The belief that SHS is harmful was associated with lower home exposure. In conclusion, adolescents in the Gulf Cooperation Council countries are exposed to concerning levels of SHS, especially in public places. These findings underscore the urgent need for stronger tobacco control policies, including comprehensive smoke-free laws covering all public venues, to protect youth from SHS exposure. Additionally, the results support the development of targeted interventions promoting smoke-free homes and social norms against smoking.