Background/Objectives: Finerenone improves cardiovascular and renal outcomes in diabetic kidney disease (DKD), but hyperkalemia remains a key safety concern. Patients with elevated baseline potassium levels (≥ 4.9 mEq/L) are largely excluded from clinical trials, and real-world data in this population are scarce. Methods: In this retrospective multicenter cohort study derived from the FINE-TURK cohort, adults with DKD who initiated finerenone with baseline serum potassium ≥ 4.9 mEq/L were included. The primary outcome was clinically significant hyperkalemia (CSH) (≥ 5.5 mEq/L) within three months. Multivariable logistic regression analyses were used to identify associated factors, with multiple sensitivity analyses performed. Results: 166 patients were included, of whom 47 (28.3%) had baseline potassium levels between 5.1 to 5.5 mEq/L. Of the 166 patients, 35 (21.1%) developed CSH, and 10 (6%) patients had follow-up potassium ≥ 6.0 mEq/L. 126 (76.8%) patients required no intervention, 24 (14.6%) were initiated on potassium binders, and finerenone was discontinued only in 12 (7.3%) patients. Baseline eGFR, baseline urinary albumin, loop diuretic use and 20mg finerenone dose were associated with CSH. In contrast, baseline serum potassium was not associated with CSH. Conclusions: In patients with DKD and elevated baseline potassium levels, finerenone initiation was associated with manageable rates of hyperkalemia. Our findings support the cautious use of finerenone in selected patients under close monitoring, as well as highlight the need for a multidimensional approach to hyperkalemia risk assessment.