This book first briefly reviews illumination optics and the basic technique of Zemax non-sequential design, then describes step-by-step, from beginning to completion, the process of modeling and designing illumination optics using Zemax non-sequential raytracing. Sixteen modeling examples and six design examples are described in this book. All of the details about these examples, including Non-Sequential Component Editor boxes, Merit Function Editor boxes, and the web links of Zemax files, are provided. The modeling and design results are discussed and compared with the results obtained using wave optics or sequential raytracing. This book intends to fill the gap between published illumination optics books and the Zemax user manual to help readers rapidly obtain the skill of using Zemax non-sequential raytracing to model and design illumination optics.