Protocols improve the reproducibility and accessibility of social science research. Given deficiencies in trial protocol quality, the SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) Statement provides an evidence-based set of items to describe in protocols of clinical trials on biomedical interventions. This project introduces items in the SPIRIT Statement to a social science audience, explaining their application to protocols of social intervention trials. Additional reporting items of relevance to protocols of social intervention trials are also presented. Items, examples, and explanations are derived from the SPIRIT 2013 Statement, other guidance related to reporting of protocols and completed trials, publicly accessible trial registrations and protocols, and the results of an online Delphi process with social intervention trialists. The use of these standards by researchers, journals, trial registries, and educators should increase the transparency of trial protocols and registrations, and thereby increase the reproducibility and utility of social intervention research.