ABSTRACT This study analyzes the digital transnational advocacy network of the 2019 Hong Kong Anti-Extradition Law Amendment Bill (Anti-ELAB) movement on Twitter. We present how grassroots users strategically utilize social media for achieving diplomatic engagement with foreign actors. The Twitter network analysis and natural language processing of tweets (N = 88,800) identify the key opinion leaders and their three core grassroots frames: universal values, humanitarian concerns, and geopolitics. We find that the low threshold of Twitter participation provides additional direct channels for ordinary users to engage with foreign politicians and create their own public opinion wave. The Anti-ELAB digital transnational grassroots advocacy network was found to have more high-profile actors, such as corporations and celebrities, due to pressure from grassroots users to stand with them. Though the two traditional frames, universal values and humanitarian concerns, adopted from the organizational-centered outreach remain prevalent, grassroots users extend geopolitical frames to incorporate their cultural capital and economic power.