A key barrier to becoming a living kidney donor is an inefficient evaluation process, requiring more than 30 tests (eg, laboratory and diagnostic tests), questionnaires, and specialist consultations. Donor candidates make several trips to hospitals and clinics, and often spend months waiting for appointments and test results. The median evaluation time for a donor candidate in Ontario, Canada, is nearly 1 year. Longer wait times are associated with poorer outcomes for the kidney transplant recipient and higher health care costs. A shorter, more efficient donor evaluation process may help more patients with kidney failure receive a transplant, including a pre-emptive kidney transplant (ie, avoiding the need for dialysis). In this report, we describe the development of a quality improvement intervention to improve the efficiency, effectiveness, and patient-centeredness of the donor candidate evaluation process. We developed a One-Day Living Kidney Donor Assessment Clinic, a condensed clinic where interested donor candidates complete all testing and consultations within 1 day. The One-Day Living Kidney Donor Assessment Clinic was developed after performing a comprehensive review of the literature, receiving feedback from patients who have successfully donated, and meetings with transplant program leadership from St. Joseph's Healthcare Hamilton. A multistakeholder team was formed that included health care staff from nephrology, transplant surgery, radiology, cardiology, social work, nuclear medicine, and patients with the prior lived experience of kidney donation. In the planning stages, the team met regularly to determine the objectives of the clinic, criteria for participation, clinic schedule, patient flow, and clinic metrics. Donor candidates entered the One-Day Clinic if they completed initial laboratory testing and agreed to an expedited process. If additional testing was required, it was completed on a different day. Donor candidates were reviewed by the nephrologist, transplant surgeon, and donor coordinator approximately 2 weeks after the clinic for final approval. The team continues to meet regularly to review donor feedback, discuss challenges, and brainstorm solutions. The One-Day Clinic was implemented in March 2019, and has now been running for 4 years, making iterative improvements through continuous patient and provider feedback. To date, we have evaluated more than 150 donor candidates in this clinic. Feedback from donors has been uniformly positive (98% of donors stated they were very satisfied with the clinic), with most noting that the clinic was efficient and minimally impacted work and family obligations. Hospital leadership, including the health care professionals from each participating department, continue to show support and collaborate to create a seamless experience for donor candidates attending the One-Day Clinic. Clinic spots are limited, meaning some interested donor candidates may not be able to enter a One-Day Clinic the same month they come forward. This patient-centered quality improvement intervention is designed to improve the efficiency and experience of the living kidney donor evaluation, result in better outcomes for kidney transplant recipients, and potentially increase living donation. Our next step is to conduct a formal evaluation of the clinic, measuring qualitative feedback from health care professionals working in the clinic and donor candidates attending the clinic, and measuring key process and outcome measures in donor candidates who completed the one-day assessment compared with those who underwent the usual care assessment. This program evaluation will provide reliable, regionally relevant evidence that will inform transplant centers across the country as they consider incorporating a similar one-day assessment model.