It is our pleasure to present this Special Issue on "Data-Driven Approaches for Complex Industrial Systems" of the IEEE TRANSACTIONS ON INDUSTRIAL INFORMATICS, which provides a forum for researchers and practitioners to report recent results on data-driven methods with applications to complex industrial systems, and to identify critical issues and challenges for future investigations in this field. Roughly, data-driven methods can be categorized into three sets, i.e., data-driven modeling, data-driven monitoring and fault diagnosis, and data-driven control and optimization (cf. Fig. 1). In this Special Issue, 13 papers are selected with novel contributions in data-driven modeling, data-driven monitoring and diagnosis, data-driven control and their industrial applications, respectively.