This text is designed as a practical introduction to quantum chemistry. Quantum chemistry is applied to explain and predict molecular spectroscopy and the electronic structure of atoms and molecules. In addition, the text provides a practical guide to using molecular mechanics and electronic structure computations including ab initio, semi-empirical, and density functional methods. The use of electronic structure computations is a relevent subject as its applications in both theoretical and experimental chemical research are increasingly prevalent. The chemistry student’s interest should be established early on in the text where quantum mechanics is developed by applying it to molecular spectroscopy. Questions throughout the text labelled as chemical connection and points of further understanding focus on conceptual understanding and consequences of quantum mechanics. These questions can be used as a basis for classroom discussion, which may encourage co-operative learning techniques.