This textbook for a one-semester course in Digital Signal Processing and Filter Design is suitable for undergraduate students of Electrical and Electronics Engineering, Electronics and Instrumentation Engineering, Instrumentation and Control Engineering, Electronics and Communication Engineering, Computer Science and Engineering, and Information Technology. Besides, it will also be a useful text for students pursuing applied sciences degree courses in Electronics, Computer Science, Computer Applications, and Information Technology. Though DSP is often treated as a complicated theoretical subject, this book through several worked examples strives to provide a motivating introduction to fundamental concepts, principles and applications of DSP. Building on the basic theory of DSP, the transformations techniques of signals such as Discrete-Time Fourier Transform (DTFT), Discrete Fourier Transform (DFT), Fast-Fourier Transform (FFT), and z-transform are discussed in detail. Several chapters are devoted to design and practical implementation schemes of analog and digital filters. The design of IIR filters using the Butterworth, Chebyshev, and Inverse Chebyshev approximations is illustrated. The design of FIR filters based on the Fourier-series and frequency-sampling methods, is discussed. Owing to their importance in DSP, the differential and difference equations are discussed in the penultimate chapter. The final chapter describes some of the practical applications of DSP.