The 29-item CareGiver Oncology Quality of Life (CarGOQoL) scale measures quality of life (QoL) based on the specific characteristics of informal caregivers of patients with cancer. The 29-item CarGOQoL has been translated to numerous other languages and validated, thus confirming its validation. This study aimed to evaluate the reliability and validity of the Korean version of the 29-item CarGOQoL. We recruited 316 informal caregivers of patients with cancer. Data were collected using structured questionnaires between January 23, 2019 and November 30, 2019, and analyzed using SPSS 27.0 and Amos 23.0. Internal consistency, construct validity, convergent and discriminant validity of the items, criterion validity, and known-group validity were tested. The 10-factor model was validated by a confirmatory factor analysis (χ2 = 687.633; P < .001; normed χ2 = 2.084; comparative fit index = .922; Tucker–Lewis index = .904; standardized root mean square residual = .050; root mean square error of approximation = .059). Criterion validity was demonstrated using the World Health Organization Quality of Life instrument-short version ( r = .495-607), visual analog scale (VAS) for QoL ( r = .509), and VAS for burden ( r = −.457). The 29-item Korean version of the CarGOQoL had known-group validity according to the Eastern Cooperative Oncology Group performance status of the patients. Cronbach’s alpha coefficient for the total scale was .90. The 29-item Korean version of the CarGOQoL demonstrated acceptable validity and reliability for measuring QoL among Korean informal caregivers of patients with cancer. The 29-item Korean version of the CarGOQoL scale can be useful in Korean oncology clinical practice and research when assessing the quality of life of informal caregivers of patients with cancer.