Elevated plasma triglyceride (TG) and cholesterol concentrations are risk factors for cardiovascular diseases. We previously reported that astaxanthin (ASTX), a xanthophyll carotenoid, lowers plasma total cholesterol and TG concentrations in apolipoprotein E knockout mice. To investigate if ASTX exerts hypolipidemic effects in the diet‐induced obesity (DIO) mice and if so, to determine an effective supplementation level, male C57BL/6J mice were fed a high fat (HF) control diet (60% energy from fat) or a HF diet supplemented with 0.003%, 0.01% or 0.03% ASTX by weight for 12 wk. Only mice fed 0.03% ASTX showed a significant reduction in plasma TG levels, suggesting this level of supplementation is necessary for ASTX to have a TG‐lowering effect. Compared with control, plasma high density lipoprotein cholesterol (HDLc) levels were significantly higher in 0.03% ASTX‐fed mice without a difference in plasma non‐HDLc levels. The ASTX supplementation also decreased plasma aspartate aminotransferase levels, suggesting it protects against high fat‐induced tissue damages. In conclusion, 0.03% ASTX in diet decreased plasma TG and increased HDLc in DIO mice and therefore, it is potentially beneficial for lowering CVD risk.Grant Funding Source: USDA AFRI 2012–67018‐19290