This text provides an introduction to the topic of transcendental numbers for undergraduate and graduate students. Chapters 1 to 18 can be used for an introductory course in transcendental numbers aimed at senior undergraduates and first-year graduate students. Since the Schneider-Lang theorem is the main focus, the reader must have a rudimentary background in complex analysis. Some of the essential features of elliptic curve theory are introduced and made accessible so that the student can savor the beauty of the primary applications. The later chapters include additional, more demanding topics including Baker's theorem and its applications to the transcendence of special values of L-series; applications of Schneider's theorem and Nesterenko's theorem as they apply to special values of modular forms; and the emerging theory of multiple zeta values. This book is ideal for undergraduates and graduate students, as well as non-expert researchers wishing to learn more about transcendental numbers. The text includes many helpful exercises intended to facilitate practical mastery.