To investigate the associations between adiposity in childhood, and adiposity change from childhood to adulthood, with pregnancy hypertension. The study followed-up 985 girls from the 1985 Australian Schools Health and Fitness Survey (aged 9-15 years) who were ever pregnant in 2004-2006 and/or 2009-2011. In childhood, overweight and obesity were defined by age-sex-specific international standard for body mass index (BMI) and in adulthood as BMI ≥ 25 kg/m2. Childhood and adult abdominal obesity were defined as waist-to-height ratio (WHtR) ≥ 0.5. A subsample of adults had abdominal obesity measures (n = 549). Pregnancy hypertension was self-reported as having had high blood pressure during or due to pregnancy. Childhood overweight/obesity (relative risk [RR] = 1.66, 95% confidence interval [CI]:1.07-2.52) and abdominal obesity (RR = 2.55, 95% CI:1.34-4.85) were associated with higher risks of pregnancy hypertension after adjustment for age, socioeconomic status and parity. Further adjustment for adult BMI attenuated the association for childhood overweight/obesity which was no longer statistically significant (RR = 1.28, 95% CI:0.79-2.07). The association with childhood abdominal obesity persisted after adjustment for adult WHtR (RR = 2.15, 95% CI:1.10-4.20). Compared to participants with persistently normal BMI or WHtR, those who were overweight/obese in adulthood only (RR = 1.49, 95% CI:1.10-2.02), persistently overweight/obese (RR = 2.06, 95% CI:1.29-3.29) or persistently abdominally obese (RR = 3.09, 95% CI:1.54-6.20) had increased risks of pregnancy hypertension. Childhood adiposity was associated with increased risk of pregnancy hypertension, with the association of childhood abdominal obesity independent of adult abdominal obesity. Women who were persistently overweight/obese or abdominally obese since childhood had the highest risk of pregnancy hypertension. Copyright © 2019 International Society for the Study of Hypertension in Pregnancy. Published by Elsevier B.V. All rights reserved.