This survey of the most important properties of the Chebyshev polynomials encompasses several areas of mathematical analysis: interpolation theory, orthogonal polynomials, approximation theory, numerical integration, numerical analysis, and ergodic theory. Originally published in 1974, the text was updated in 1990; this reprint of the second edition corrects various errors and features new material, including a chapter introducing elementary algebraic and number theoretic properties of Chebyshev polynomials. AUTHOR: Theodore J. Rivlin (1926 2006) was on the staff of the IBM Research Division, Thomas J. Watson Research Center, Yorktown Heights, New York. His other Dover book is An Introduction to the Approximation of Functions.