School absences can negatively impact a child's schooling, including the loss of teacher-led lessons, peer interactions, and, ultimately, academic achievement. However, little is known about the long-term consequences of school absences for overall educational attainment and labour market outcomes. In this paper, we used data from the 1970 British Cohort Study to examine long-term associations between school absences in late childhood and individuals' educational attainment, social class, unemployment and earnings at age 42 while adjusting for a comprehensive set of confounders. Our findings show that school absences are associated with lower educational attainment but are not associated with social class destination except for increasing the likelihood of being out of the labour force after adjusting for confounders. Individuals who missed five days of school at age 10 were 5.2% more likely to have obtained no qualifications and 4.1% more likely to be out of the labour force. However, we did not find a significant association between school absences and individuals' earnings or duration of unemployment. Our findings suggest that the detrimental consequences of school absences persist beyond schooling into adulthood. Overall, this study highlights the importance of addressing school absenteeism to promote educational and labour market participation over the life course.