Hypertensive disorders of pregnancy are associated with an increased risk of adverse neurodevelopmental outcomes in children, as confirmed by a systematic review and meta-analysis of 121 studies involving 29,649,667 offspring. The study found increased unadjusted odds of autism spectrum disorder (OR 1.65; 95% CI [1.49,1.83]; p < 0.001; n = 26,727,500), attention deficit/hyperactivity disorder (OR 1.93; 95% CI [1.72, 2.17]; p < 0.001; n = 12,987,737), intellectual disability (OR 1.77; 95% CI [1.31, 2.38]; p < 0.001; n = 10,718,504), developmental delays (OR 1.77; 95% CI [1.02, 3.09]; p < 0.001; n = 2,961,195) and reduced average intelligence (MD −2.20; 95% CI [−3.35, −1.06]; p < 0.001; n = 1,150,664). Associations with autism and developmental delay lost significance after adjustment for gestational age and birth weight, results for IQ remained significant after adjustment for birth weight but not for gestational age. Adjusted analyzes could not be performed for attention deficit/hyperactivity disorder and intellectual disability due to lack of studies. Sensitivity analyzes confirmed the stability of the results after excluding studies with a high risk of bias. The study emphasizes the need for early intervention in children of mothers with hypertensive disorders of pregnancy.