Objective:To conduct a scoping review of mobile app-based weight management studies in patients with breast cancer.Methods:The studies related to weight management in patients with breast cancer based on mobile apps in nine Chinese and English databases, including PubMed, Embase, Cochrane, EBSCOhost, Scopus, Sinomed, VIP database, Wanfang Database and China National Knowledge Infrastructure (CNKI), were systematically searched with the terms of “breast cancer” “weight management” “mobile health” and “weight”. The search period was from the establishment of the databases to July 29, 2022. The literature was screened, and data were extracted and summarized based on the Omaha system.Results:A total of 7 literatures were included, all were in English. The mobile apps included in the studies varied with sample sizes, ranging from 10 to 356 cases. Six of the studies involved breast cancer patients who had completed surgery or chemoradiotherapy, and none of the studies involved breast cancer patients undergoing chemotherapy. Forms of intervention included exercise or diet alone and a combination of both exercise and diet, and most studies had shown good intervention effects. According to the Omaha intervention system, the most commonly extracted intervention component was self-management advice, which was offered to patients in six studies, and none of the intervention studies included intervention components related to case management.Conclusions:An intervention for weight management based on mobile apps in breast cancer patients has a good effect and is feasible. However, there is a limited number of related studies, and there is a lack of interventional research specifically targeting patients during chemotherapy, which still needs to be actively carried out.