Anecdotal and scholarly reports have long highlighted that women in the media are more likely to face hostility and abuse from the public both directly and indirectly as a response to their reporting when compared to their male counterparts. These disparities may be amplified on social media, where toxic and negative content is increasingly prevalent. To date, however, there is little in the way of comprehensive analysis on the exact extent to which female journalists may be subject to more negativity online, nor of the exact contexts in which this negativity is most likely to occur. With this in mind, this paper analyses the content of over 50,000,000 replies sent to over 1,400 U.S. media accounts on Twitter across 2022. Based on a first-of-kind machine learning classifier of what is specifically defined as “targeted negativity” in online messaging, the results show, centrally, that female journalists do indeed receive higher levels of targeted negativity than male journalists, with this disparity being greatest among journalists who work for more ideologically extreme media outlets. Importantly, the specific content of a journalists reporting is also a central driver of negativity, with reporting by female journalists on politics and in particular about “women’s issues” receiving the highest levels of negative responses. These results provide large-scale insights into hostile engagement faced by journalists on social media, as well as into the specific reporting contexts in which women journalists may face the most negative engagement from the public.