Background and ObjectiveDespite the high burden of respiratory disease amongst Indigenous populations, prevalence data on spirometric deficits and its determinants are limited. We estimated the prevalence of abnormal spirometry in young Indigenous adults and determined its relationship with perinatal and early life factors.MethodsWe used prospectively collected data from the Australian Aboriginal Birth Cohort, a birth cohort of 686 Indigenous Australian singletons. We calculated the proportion with abnormal spirometry (z‐score <−1.64) and FEV1 below the population mean (FEV1% predicted 0 to −2SD) measured in young adulthood. We evaluated the association between perinatal and early life exposures with spirometry indices using linear regression.ResultsFifty‐nine people (39.9%, 95%CI 31.9, 48.2) had abnormal spirometry; 72 (49.3%, 95%CI 40.9, 57.7) had a FEV1 below the population mean. Pre‐school hospitalisations for respiratory infections, younger maternal age, being overweight in early childhood and being born remotely were associated with reduced FEV1 and FVC (absolute, %predicted and z‐score). The association between maternal age and FEV1 and FVC were stronger in women, as was hospitalization for respiratory infections before age 5. Being born remotely had a stronger association with reduced FEV1 and FVC in men. Participants born in a remote community were over 6 times more likely to have a FEV1 below the population mean (odds ratio [OR] 6.30, 95%CI 1.93, 20.59).ConclusionYoung Indigenous adults have a high prevalence of impaired lung function associated with several perinatal and early life factors, some of which are modifiable with feasible interventions.