The purpose of this study was to assess relationships between liver-corrected T1 (cT1) values (adjusted for T2* effect, MRI system manufacturer, and field strength) and histologic inflammation and fibrosis in 35 participants (15 women and girls, 20 boys and men; median age, 16.0 years) with autoimmune liver disease. At multivariable analysis, inflammation score (β = 15.5) and sex (β = 56.0 [female]) were independent predictors of cT1, and fibrosis score (β = 32.3) and age (β = 5.5) were independent predictors of cT1 IQR. Liver T1 may have relevance for assessing liver inflammatory activity and fibrosis stage.