Aims: Child maltreatment (CM) is a serious public health issue, affecting over half of all children globally. Although most CM is perpetrated by parents or caregivers and their reports of CM is more accurate than professionals or children, parent or caregiver report instruments measuring CM have never been systematically evaluated for their content validity, the most important psychometric property. This systematic review aimed to evaluate the content validity of all current parent or caregiver report CM instruments. Methods: A systematic literature search was performed in CINAHL, Embase, ERIC, PsycINFO, PubMed, and Sociological Abstracts; gray literature was retrieved through reference checking. Eligible studies needed to report on content validity of instruments measuring CM perpetrated and reported by parents or caregivers. The quality of studies and content validity of the instruments were evaluated using the COnsensus-based Standards for the selection of health Measurement INstruments guidelines. Results: Fifteen studies reported on the content validity of 15 identified instruments. The study quality was generally poor. The content validity of the instruments was overall sufficient, but most instruments did not provide high-quality evidence for content validity. Conclusions: Most instruments included in this review showed promising content validity. The International Society for the Prevention of Child Abuse and Neglect Child Abuse Screening Tool for use in Trial appears to be the most promising, followed by the Family Maltreatment–Child Abuse criteria. However, firm conclusions cannot be drawn due to the low quality of evidence for content validity. Further studies are required to evaluate the remaining psychometric properties for recommending parent or caregiver report CM instruments.