Collective trauma is the outcome of traumatic incidents that necessitate collective self-reflection and create a need for public discourse. Access to social media allows individuals to shape event coverage beyond what is put forth by mainstream media through hashtag-based communities. The death of Sahar Khodayari, or “Blue Girl,” an Iranian woman who committed suicide after being sentenced to prison for appearing in a sports stadium dressed as a man, is one such event that became a collective trauma. The current study sought to examine the collective trauma reaction among Farsi-speaking Twitter users in response to Khodayari's death as represented in public tweets. The overall pool of data consisted of 8,653 tweets containing at least one of four hashtags (i.e., #BlueGirl, #Blue_Girl,, # #), posted September 9–24, 2019, as well as 603 tweets posted on the anniversary of the event 1 year later. Using thematic analysis, we identified three main themes within these public tweets representing different responses to Khodayari's death: social justice, awareness, and process. In undemocratic countries, like Iran, where there are limited free physical spaces for public gatherings, social media provides a platform for people to come together after tragic events to express emotions and discuss thoughts and actions. The present findings demonstrate that Twitter allowed Farsi-speaking users to demand social justice, share awareness about #BlueGirl, and process their emotions and thoughts accordingly. Therefore, social media may provide a window into the collective trauma experience, and it may also serve as a new mode of studying trauma on new platforms.