The Student Subjective Wellbeing Questionnaire is a measure designed to assess adolescents' subjective wellbeing at school. The article presents our work toward adapting the SSWQ to the Polish cultural context. The Polish translation of the SSWQ, the KIDSCREEN-27, and the State-Trait Anxiety Inventory for Children (STAIC) were administered to 818 students aged 10-16 years, who were in Grades 5-8 of elementary school. As a result of a language adaptation process, a 16-item questionnaire was created, comprising four subscales, like the original version: School Connectedness, Joy of Learning, Educational Purpose, and Academic Efficacy. Confirmatory factor analysis demonstrated that both the SSWQ-PL first-order measurement model, which consisted of the above four fully correlated factors, and its second-order measurement model, which structured these four first-order factors as indicators of one second-order factor (i.e., student subjective wellbeing), showed good data-model fit and high internal consistency with the present sample. Cronbach's alpha for the overall score was 0.87 and H coefficient was 0.94. The Pearson product-moment correlation coefficient between the total SSWQ-PL scores at two time points was 0.88 (p < 0.01), which suggests that the SSWQ-PL is reliable over time. Results showed that the SSWQ-PL had appropriate convergent and divergent validity with scores from the KIDSCREEN-27 and STAIC, which means it can be a useful measure to assess students' subjective wellbeing in school counseling.