Disclosed herein are dihydroceramide desaturase 1 (Des1) inhibitor compounds and compositions, which are useful in the treatment of diseases, such as metabolic, cardiovascular, fibrotic, autoimmune/chronic inflammatory diseases, cystic fibrosis, various cancers, neurodegenerative diseases, lipid storage disorders, and ischemia/reperfusion injury, where inhibition of Des1 is expected to be therapeutic to a patient. Methods of inhibition of Des1 activity in a human or animal subject are also provided.