Very preterm (VPT) infants are at high risk of motor impairments such as cerebral palsy (CP). Currently, qualitative findings from structural MRI and outcomes from clinical assessments are insufficient for early, accurate diagnosis of CP. In a multicenter cohort of 263 VPT infants, we derived macro and microstructural biomarkers of sensorimotor white matter tracts from term-equivalent age diffusion MRI. We observed consistent negative associations between these metrics – fiber density, fiber cross-section, and combined fiber density and cross-section – and early diagnosis of CP. These findings enhance our understanding of the pathophysiology of CP in VPT infants.