INTRODUCTION: Preterm birth (PTB) affects 1 in 10 births in the USA and is associated with near-term and long-term health consequences. This study assesses social and geographical disparities in adverse birth outcomes and associated risk factors in Alaska. METHODS: We examined birth records for 218 222 singleton live births in Alaska between 2000 and 2020. We described the distribution of PTB, very PTB, and low birth weight by geographical region, assessed risk factors for adverse birth outcomes, investigated how racial and ethnic differences in birth outcomes may be related to behavioural and social risk factors, and investigated how the unique transportation network in the state may affect adverse birth outcomes. RESULTS: There was an increased risk of PTB among births to mothers over 35 years of age (adjusted OR, AOR: 1.26
95% CI: 1.20, 1.33), with prepregnancy diabetes (AOR: 3.42
95% CI: 3.00, 3.90) or hypertension (AOR: 2.28
95% CI: 2.08, 2.51), who used tobacco during pregnancy (AOR: 1.33
95% CI: 1.27, 1.40), and who received <
11 prenatal care visits (AOR: 2.66
95% CI: 2.56, 2.77). Racial disparities in PTB persisted after adjustment for behavioural and healthcare-related risk factors. Nearly 40% of births took place outside the mother's community of residence, and there was an increased risk of PTB associated with travelling for birth. CONCLUSIONS: PTB continues to be a persistent issue in Alaska, particularly among non-white mothers. Our findings regarding prenatal care utilisation, pre-existing health conditions, and tobacco use during pregnancy can support public health interventions to decrease the risk of adverse birth outcomes.