With ever-increasing concerns on energy crisis and environmental protection, there is a fast-growing interest in wind power generation systems. As electric machines and drives are core components in wind turbines, it is a pressing need for researchers and engineers to develop advanced electric machines and drives for wind power generation. This paper provides a thorough review of modern electric machines and drives for wind power generation, with emphasis on machine topologies, operation principles, performance characteristics, as well as control strategies. The key features of electric machines and drives including their merits and demerits, e.g. torque/power density, efficiency, and cost, are compared and summarised. Trade-offs involved in various presented methods and strategies are highlighted. The major challenges and difficulties, which electric machines and drives for wind power generation are facing, are discussed. Moreover, the developing trends and opportunities are revealed, while the latest development is also discussed.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.