Chronic hepatitis C virus (HCV) infection is an important public health issue owing to its worldwide prevalence and its profound effects on patients’ well-being and function. We developed a new patient self-report tool, the HCV patient-reported outcomes (HCV-PRO) instrument, to assess patients’ function and well-being reflecting both HCV disease and treatment burdens. Items were developed through a qualitative phase including scientific literature review, expert appraisal, and semi-structured patient interviews. The item pool was initially psychometrically tested in 60 adult HCV patients, 18 years of age or older at a university hepatology clinic. A final psychometric test was conducted in 241 members of the online Harris International Panel to examine scale reliability, confirm factor structure, and assess convergent and discriminant validity. A single-factor 16-item HCV-PRO instrument demonstrated good model fit. The HCV-PRO items and total score (range 0–100) showed excellent item response (few floor and ceiling effects) and reliability (alpha > 0.90). Convergent validity was established from moderate to high (r > 0.50) correlation with symptom burden, life satisfaction (ladder of life), and SF-36v2 scales scores. Mean HCV-PRO scores differentiated between currently treated patients, those previously treated, and patients never treated (p < 0.01), suggesting strong known-groups validity. The results provide initial evidence that the HCV-PRO can yield reliable and valid measurement of the effects of HCV and its treatment on the well-being and function of HCV-infected patients.