Helplines are generally a population-level resource for providing free, timely, easy-to-access, and anonymous counseling and/or information. Helplines have been developed and widely implemented for specific use by young people. The current study aimed to systematically review the literature to determine the status of research into the use of helplines among young people. Following the PRISMA checklist, 5 electronic databases were searched using relevant terms for literature published until May 2020. The extracted studies were summarized with the intention of identifying key themes that highlighted common findings, key implications, and important gaps in understanding. A total of 52 articles fitting study inclusion criteria were identified. Most studies were quantitative papers from the United States and Australia. The types of helpline interactions studied were a mixture of telephone-based and SMS/text-based interactions. Three major themes were identified: awareness of and engagement with helpline services, nature of problems faced by young people, and service-related factors. Subthemes were use and awareness, barriers to help seeking, psychosocial problems, suicidality, telephone- versus text-based interactions, counselor-caller interaction, and provision of services to historically and systemically marginalized groups. It appears that helplines may provide a beneficial service to youths, and that myriad psychosocial concerns provide the basis for calling. The literature is limited by a lack of controlled trials, on one hand, and complex methodological/ethical barriers preventing such trials, on the other hand. However, more research is needed before conclusions regarding effectiveness in youths can be made, particularly for services provided to systemically marginalized groups and using online text-based approaches. Copyright © 2020 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.