AbstractThis is the protocol for a Campbell systematic review. The objectives are as follows: To identify methods used to assess the risk of outcome reporting bias (ORB) in studies included in recent Campbell systematic reviews of intervention effects. The review will answer the following questions: What proportion of recent Campbell reviews included assessment of ORB? How did recent reviews define levels of risk of ORB (what categories, labels, and definitions did they use)? To what extent and how did these reviews use study protocols as sources of data on ORB? To what extent and how did reviews document reasons for judgments about risk of ORB? To what extent and how did reviews assess the inter‐rater reliability of ORB ratings? To what extent and how were issues of ORB considered in the review's abstract, plain language summary, and conclusions?