C₁₈H₂₆O₃

The molecular formula C₁₈H₂₆O₃ (molar mass: 290.40 g/mol) may refer to:

• Inocoterone acetate, nonsteroidal antiandrogen
• Isanolic acid, rare fatty acid
• Octyl methoxycinnamate, a sunscreen ingredient
• Oxabolone, an anabolic steroid