Synthetically grown high-quality single crystal diamond is an excellent base material for quantum photonics. Planar single crystal diamond substrates several square millimeters in size are nowadays commercially available. They can be precisely structured using micro- and nanofabrication techniques that are common in the semiconductor industry. This chapter provides an introduction to diamond substrate preparation by laser cutting, grinding, polishing, and cleaning, compares typical lithography techniques and their suitability for diamond processing, and summarizes experimentally reported diamond patterning approaches, including high-temperature vapor-based etching, catalyst-assisted etching, reactive ion etching, and direct patterning by focused ion beam. A selection of micro- and nanostructures realized in single crystal diamond is presented. This chapter is intended to serve as a practical guide for the selection of diamond micro- and nanostructuring methods suitable for emerging quantum photonic applications.