Due to the Ubiquity of Concrete in the Urban Environment and the Upscaling of Nanomaterial Production, the Incorporation of Nanoparticles into Cementitious Materials Has Gained Increased Attention. This Chapter Focuses on Understanding the Self-Cleaning Properties of Nano TiO2-Engineered Cementitious Materials, Including Self-Cleaning Mechanism and Types (Section 8.2), Effect of Nano-TiO2 on Cementitious Substrates (Section 8.3), and Self-Cleaning Performance and Application (Section 8.4). Two Attributes Are Studied to Understand the Self-Cleaning Capacity of These Materials: TiO2-Induced Photocatalysis and Surface Superhydrophilicity. Future Study Should Focus on the Expanding Use of Visible-Light-Responsive Nano Photocatalysis in Cementitious Materials.