Child maltreatment is a global public health and child rights crisis made worse by the ongoing COVID-19 pandemic. While understanding the breadth of the child maltreatment crisis is foundational to informing prevention and response efforts, determining accurate estimates of child maltreatment remains challenging. Alternative informants (parents, caregivers, a Person Most Knowledgeable—PMK) are often tasked with reporting on children’s maltreatment experiences in surveys to mitigate concerns associated with reporting child maltreatment. The overall purpose of this study was to examine child maltreatment reporting practices in surveys by PMKs for children and youth. The research question is: “What is the nature of the evidence of child maltreatment reporting practices in general population surveys by PMKs for children and youth?” A rapid scoping review was conducted to achieve the study’s purpose. A search strategy was conducted in nine databases (e.g., MEDLINE, EBSCO, Scopus, Global Health, ProQuest). The findings from this review indicate that most studies involved PMK informants (i.e., maternal caregivers), included representative samples from primarily Western contexts, and utilized validated measures to assess child maltreatment. Half of the studies assessed involved multi-informant reports, including the PMKs and child/youth. Overall, the congruence between PMK-reported and child/youth-reported child maltreatment experiences was low-to-fair/moderate, and children/youth reported more maltreatment than the PMKs.