Cardiomyopathy in type 1 diabetes (T1D) is accompanied by altered cardiac energetics, impaired mitochondrial function and oxidative stress. We showed previously increased cardiac expression of Krüppel-like factor 5 (KLF5) and Peroxisome Proliferator Activated Receptor (PPAR)α at late T1D stage in mice. We confirmed that KLF5 expression is higher in cardiomyocytes of diabetic patients than in non-diabetic individuals. Mechanistic analyses in human cardiomyocyte cells (AC16) and in mice with cardiomyocyte-specific FOXO1 deletion (αMHC- Foxo1 -/- ) revealed that FOXO1 activation accounts for the increased KLF5 expression via direct binding on Klf5 promoter. Both pharmacologic and cardiomyocyte-specific inhibition of KLF5 alleviated diabetic-related cardiac dysfunction. Accordingly, mice with doxycycline-mediated cardiomyocyte-specific KLF5 constitutive expression (αMHC-rtTA- Klf5 ) recapitulated cardiomyopathy even in the absence of T1D. We also showed that diabetic PPARα -/- mice had elevated cardiac KLF5 expression and cardiac dysfunction, suggesting that KLF5-driven diabetic cardiomyopathy is PPARα-independent. Furthermore, cardiomyocyte KLF5 upregulation was associated with oxidative stress, increased NADPH oxidase (NOX)4 expression, lower NADPH levels and impaired cellular Ca 2+ handling. Conversely, KLF5 inhibition prevented NOX4 upregulation and alleviated cardiac superoxide formation. Lipidomic analysis followed by Euclidean clustering showed strong correlation of lipidome profiles between αMHC-rtTA- Klf5 mice and diabetic C57BL/6 mice, while diabetic αMHC- Klf5 -/- mice and diabetic C57BL/6 mice that were treated with pharmacologic KLF5 inhibitor grouped with the non-diabetic C57BL/6 mice. Further analysis of individual lipid species showed increased ceramide accumulation in diabetic C57BL/6 and αMHC-rtTA- Klf5 mice that was reversed upon KLF5 inhibition. Treatment of αMHC-rtTA- Klf5 mice and diabetic C57BL/6 mice with the antioxidant LGM2605 improved partially cardiac dysfunction. In conclusion, cardiomyocyte KLF5 expression is activated by FOXO1 and drives diabetic cardiomyopathy in a non-PPARα-dependent manner, suggesting KLF5 inhibition as a therapeutic intervention in T1D cardiomyopathy.