How can data science and artificial intelligence (AI) methods be used in the urban design process? In this chapter, we argue that data science can be integrated at every stage of the urban design process, assisting rather than replacing human experts. We illustrate this process through four sequential stages: discovering knowledge from contextual data, digital reconstruction for augmented design, applying generative methods in design development, and using causal methods and simulations for design prediction and evaluation. To demonstrate, we present a case study on street frontage analysis, focusing on data science methods such as image classification and image generation to transform the urban design workflow. We conclude by discussing opportunities and challenges, such as the need to collect multi-modal urban design data and the importance of responsible urban design education and practice.