The pursuit of urban sustainability is considered central to sustainable development and is a key objective of the global Sustainable Development Goals (2015) and the New Urban Agenda (2016). This thesis aims to contribute to debates on urban sustainability by providing insights as to the role of actors participating in processes of governing for urban sustainability, with particular focus on the municipal organisation.The thesis employs an interdisciplinary approach to illustrate divergent approaches to governing for urban sustainability, with reference to empirical studies of strategic planning processes in municipalities in selected North-western European countries -Sweden, Switzerland and The Netherlands.These studies address themes including climate change, sustainable transport and multi-level governance. The thesis provides a broad overview of theoretical discussions related to governing, strategy and planning, the role of actors in governing for urban sustainability, and the particular importance of climate change as a challenge for urban sustainability.A number of research gaps are identified and addressed in two research questions, focusing on the organisation and practice of processes of governing for urban sustainability, and the factors influencing actors participating in such processes. The thesis responds to these research questions with reference to five appended papers, which illustrate different dimensions of governing for urban sustainability.The first paper concerns the organisation of processes to develop energy and climate strategies in Swedish municipalities, and the second paper highlights the experiences of actors participating in such processes. The third paper presents results from a survey illustrating the expectations of stakeholders active in governing transport in the city of Norrköping, Sweden.In the fourth paper, the development and implementation of policies aiming for sustainable transport and urban sustainability in Basel, Switzerland, are discussed. In the final paper, cooperation through transnational municipal networks is explored with reference to the World Ports Climate Declaration, an initiative of the city of Rotterdam.ii The thesis confirms the presence of five factors -capacity, mandate, resources, scope and will -that shape the "strategy space" of actors and play an important role in conditioning the form and content of processes of governing for urban sustainability. The thesis suggests that the ways in which a municipal organisation perceive and mobilise the five factors will strongly determine the extent of its sustainability strategy space.In sum, municipal organisations and other actors participating in processes of governing for urban sustainability need to mobilise the five factors and expand their strategy space, in order to achieve vertical and horizontal alignment of strategic objectives and facilitate implementation that delivers transformative change.iii Populärvetenskaplig sammanfattning Hållbar stadsutveckling är nödvändig för hållbar utvecklin...