Hypothyroidism was confirmed to be associated with both dyslipidemia and renal dysfunction. However, the impact of thyroid function on the relationship between serum lipid levels and renal function has never been given sufficient attention. In this large-scale multicenter cross-sectional study, the ratio of triglyceride to high-density lipoprotein cholesterol (TG/HDL) and the prevalence of hypothyroidism in CKD subjects were significantly higher than those in non-CKD ones (P < 0.001). After adjustment for potential confounding factors, TG/HDL was shown to be significantly associated with serum Cr levels (β = 0.551; 95%CI, 0.394-0.708), and eGFR (β = -0.481; 95%CI, -0.731--0.230). The risk for CKD was significantly increased as TG/HDL ratio was elevated (adjusted odds ratio = 1.20; 95%CI, 1.11-1.27). These significant associations were found among subjects with euthyroidism and hypothyroidism rather than hyperthyroidism. Furthermore, the associations between TG/HDL and Cr or CKD status were significantly greater in hypothyroidism than those in euthyroidism (P < 0.05). These results suggested that elevated TG/HDL ratio was associated with renal dysfunction; it exhibited a significantly stronger association with Cr and CKD in hypothyroidism than in euthyroidism. Therefore, more attention should be paid on lipid profile to prevent or delay the occurrence and progression of renal dysfunction, especially for those with hypothyroidism.