Organizations face two major transformations: sustainability and digital transformation. Existing literature refers to them as twin or co-transformation. Co-transformation suggests that organizations tackle sustainability and digital transformation as one strategic concern. But how does this change organizations’ strategizing for sustainability, for digital, or for co-transformation? The environmental non-governmental organization Greenpeace kick-started its digital transformation in 2020. For them, sustainability has been a key concern since their foundation in 1971. Accordingly, Greenpeace, when strategizing for digital transformation, considers how their digital transformation reflects environmental and social sustainability. This makes their digital transformation process a revelatory case for unpacking strategizing for digital–sustainable co-transformation. In his talk, Markus P. Zimmer presents insights from an ongoing case study of Greenpeace’s digital–sustainable co-transformation.