Today, and for the foreseeable future, organizations will face ever-increasing levels of complexity and uncertainty. Many believe that enterprise architecture (EA) will help organizations address such difficult terrain by guiding the design of adaptive and resilient enterprises and their information systems. This paper presents the Grand Challenges that we believe will challenge organizations in the future and need to be addressed by enterprise architecture. As a first step in using enterprise architecture as a solution for overcoming identified challenges, the Zachman Enterprise Architecture Framework is used to guide and structure the discussion. The paper presents the Grand Challenges and discusses promising theories and models for addressing them. In addition, current advances in the field of enterprise architecture that have begun to address the challenges will be presented. In conclusion, final thoughts on the future of enterprise architecture as a research field and a profession are offered.