The AGU Enabling FAIR Data project’s Repository Guidance Targeted Adoption Group developed a detailed decision tree to understand all possible criteria that researchers should consider when determining an appropriate repository in which to deposit their data. The tree is applicable to most domains of research, funding scenarios and project stages (i.e., proposal vs. project completion), and considers requirements with which the researcher may need to comply and the availability of suitable repositories to meet their needs. The decision tree was used to inform the development of the Repository Finder tool (http://repositoryfinder.datacite.org), a new resource designed for use by researchers in need of locating a “repository home”. With more than 2,200 data repositories available worldwide, this tool helps to meet a crucial need of researchers to learn about and select the most appropriate repository to deposit their data. It was initially scoped for application in the Earth, space, and environmental science repositories, but its design should enable it to to scale to include other domains and other, emerging criteria or lists of recommended repositories.