Patients undergoing hemodialysis (HD) face severe dietary potassium restrictions, reducing their quality of life (QOL) and potentially worsening their prognosis. Sodium zirconium cyclosilicate (SZC) is a novel selective potassium binder that lowers potassium levels, with minimal effects on other electrolytes. The Y-QOL study will evaluate whether SZC can improve QOL by easing the burden of dietary restrictions. This 8-week, multicenter, randomized, parallel-group, open-label trial will enroll 200 outpatients with hyperkalemia (potassium level 5.5–6.4 mEq/L after a 2-day inter-dialytic interval) on thrice-weekly HD. Participants will be randomized to receive SZC (starting dose 5 g on non-dialysis days, adjustable to 15 g based on serum potassium levels) plus dietary guidance, or dietary guidance alone to maintain serum potassium levels at 4.0–5.4 mEq/L. The primary endpoint is changes in The 7-item QOL Disease-specific Impact Scale (QDIS-7) scores at week 8 from baseline. Secondary endpoints include additional QOL scores, nutritional status, inflammation markers, Bristol Stool Form Scale, serum potassium reduction, and safety. Recruitment began on January 24, 2024, and the study will conclude on March 31, 2026. The Y-QOL study aims to determine the effectiveness of SZC in improving QOL by reducing serum potassium levels in patients with hyperkalemia undergoing HD.