Diabetic nephropathy (DNP) is a serious complication of type 2 diabetes mellitus (T2D), leading to early disability and mortality from end-stage renal failure. Experimental and clinical studies have shown the leading role of oxidative stress-induced damage to macromolecules, including DNA, in the development and progression of DNF against the background of hyperglycemia. On the contrary, repair of these DNA lesions serves as a signal to end ongoing oxidative stress. The key DNA repair enzyme is 8-oxoguanine DNA glycosylase, encoded by the OGG1 gene. The aim of this study was to analyze the associations of five polymorphic variants (rs2072668, rs1052133, rs293795, rs2304277, and rs6443265) of the OGG1 gene with the risk of developing DNF in patients with type 2 diabetes. The study included 1461 patients with type 2 diabetes, 577 of whom were diagnosed with DNF. DNA genotyping was performed by real-time polymerase chain reaction using allele-specific fluorescently labeled probes. Associations were established between the rs293795-G/G genotype (OR = 1.97, 95% CI = 1.23-3.16, p = 0.007) and the rs2072668C-rs1052133C-rs293795G-rs2304277G-rs6443265C haplotype (OR = 1.30, 95% CI = 1.06-1.60, p = 0.012) of the OGG1 gene with a predisposition to DNF in the background of T2D. Moreover, six OGG1 diplotypes associated with an increased risk of DNF and one diplotype associated with a reduced risk of DNF in patients with T2D were identified. Thus, in our study, we presented for the first time data on the association of the OGG1 gene polymorphism with DNF, which creates a scientific foundation for further research on the contribution of disturbances in the DNA oxidative damage repair system to the development of microvascular complications of T2D.