With the majority of the global population living in cities, urbanisation and climate crisis have become urgent planetary issues. This Element examines 'urban eco-performance', exploring how theatre and performance intersect with urbanisation and ecological crises to reimagine equitable urban futures. Through rigorous ecodramaturgical analyses, this Element critiques the colonial and capitalist systems shaping cities and highlights performance's role in addressing climate justice. Performances from Canada, Mexico, Nigeria, Taiwan, UK and USA, as well as Indigenous performances, are brought together for the first time to examine how they challenge the human/nature divide, revealing cities as vibrant ecological spaces. These performances foreground underrepresented voices and reframe cities as 'bio-urban' spaces. This Element integrates decolonial and intersectional ecological frameworks over three thematic sections: Living Cities, Petro-Cities and Urban Futures Against the Apocalypse. It argues for justice for marginalised communities while envisioning cities as interconnected ecosystems that can foster collective action and ecological resilience.