This article examines Myanmar ethnic minorities’ diverse responses to the 2021 military coup. The coup prompted widespread mobilization for a national alliance that aims to replace the junta with a federal democracy. For minority actors this resistance could offer a unique opportunity to advance their demands for political autonomy, yet their responses diverged. Some joined the alliance; others declined, or accepted junta offers. Based on original interviews, this analysis unpacks the positions of ethnic rebels, civil society organizations, and parties. It suggests rebels’ strategies were influenced by their relations with civil society and military strength. Most ethnic parties avoided resistance, as they feared junta retaliation and distrusted the ousted National League for Democracy. Ethnic civil society organizations played a key coordinating role during alliance formation, enabled by its campaign experience and networks. The article’s insights into interethnic cooperation and minorities’ varied situations can benefit international actors seeking resolutions of Myanmar’s post-coup conflict.