This thesis sets out to empirically examine the relationship between international campaigns which originate in and continue to be driven by Twitter and domestic women’s rights. The study looks at eight campaigns targeting seven countries, with over 1 million Tweets and 1500 pieces of legal evidence. The study looks at four aspects of legal change: legislation, institutionalisation, law enforcement, and dialogue with international human rights bodies. The campaigns are explored in four areas as well, looking at persistence, users, engagement, and Tweet content. The study sets out to provide evidence for whether hashtag campaigns can contribute to domestic legal change, and, if so, if certain campaign behaviours are more associated with change and in what way. Overall, this study has found that hashtag campaigns can contribute towards domestic legal change, both positively and negatively. Two campaigns resulted in backsliding, three had no impact, two led to tactical concessions, and one campaign showed some elements of tentative success. Campaigns which are domestically driven, with a high level of foreign-attention, showing persistence, engagement, and consistency are more likely to see to positive legal outcomes. Conversely, campaigns which lack in domestic drive, can be seen as ‘foreign meddling’, and fail to achieve persistence, engagement, or consistency are more likely to see to negative outcomes.