Statistical mechanics provides a framework for understanding macroscopic properties of many-body systems (such as solids, liquids, or gases) from the underlying dynamics of the constituent particles. Topics to be introduced include microstates, entropy, partition functions, free energy and various ensemble formalisms. These tools will be used to calculate thermodynamic and equilibrium properties of both classical and quantum mechanical systems from the ideal gas, to ferromagnetism, to Bose-Einstein condensation.