Entropy for Biologists: An Introduction to Thermodynamics is an introductory book for people in the life sciences who wish to master the concepts of thermal physics without being forced to a degree and rate of symbol manipulation which is foreign to their patterns of thought. The book opens with a chapter on temperature, followed by separate chapters that discuss the concepts of energy, kinetic theory, total energy, the second law of thermodynamics, entropy, and probability and information theory. Subsequent chapters deal with statistical mechanics and its relation to thermodynamics, free-energy functions, applications of the Gibbs free energy and the Gibbs chemical potential, and measurement in thermal physics. The book is primarily directed at those graduate and advanced undergraduate students of biology and biochemistry who wish to develop a sense of confidence about their understanding of the thermal physics which will be useful in pursuing their work. It may also prove useful to professionals who wish to bolster their knowledge in this area.