During the spring of 2019, approximately 1.6 million people in over 1700 cities worldwide participated in strike action to raise public awareness of government inaction on climate change. The large proportion of youth and young people mobilized through these climate strikes was unprecedented. However, we know very little so far about who these young people are, how they participated, and what it will mean for them academically over the short and long term. To address these knowledge gaps, we accessed a unique administrative longitudinal dataset consisting of 65,085 youth, enrolled in 723 compulsory education schools in Flanders. We aimed to investigate the socio-demographic profiles of students who were absent from school due to participating in the School Strikes for Climate. The results indicate that students who attended the School Strikes for Climate were predominantly females with a middle to higher socio-economic background, attending schools in an urban context. Additionally, contrary to previous research demonstrating positive correlations between absenteeism and reduced academic outcomes, missing school to attend the School Strikes for Climate did not affect these students' academic achievements at the end of the school year. In the discussion, we elaborate on the theoretical implications of our findings with regards to discussions on the personal, social, and political effects of this movement.