The challenges of environmental and sustainability governance such as dealing with competing goals, multiple interest perspectives and inherent wicked problems increasingly call for collaborative approaches in planning, policy-making, and public management. The collaboration of a diverse mix of public and private organizations is expected to bring resources, knowledge, and perspectives that may reconcile conflicts and improve policy effectiveness. As such, collaborative environmental governance contains considerable promises, seeking to restore trust in government. In this chapter, we will depict how collaborative environmental governance has emerged in current environmental and natural resource policy practice, and discuss the underlying premises for fruitful collaboration. The concept brings in ideas from a range of literatures on planning and policy studies, and overlaps considerably with the concept of network governance. We portray some of the most prominent analytical approaches to collaboration in environmental governance, and end with a section on practical implications and future research challenges.