This book is based on a series of lectures given by the author in his graduate class on star formation, taught regularly since 2009. The book is intended for graduate students or advanced undergraduates in astronomy or physics, but does not presume detailed knowledge of particular areas of astrophysics. Its goal it to provide a general overview of the field of star formation, at a level that would enable a student to begin independent research in the area. The book continues to be updated periodically to reflect developments in the field.