This book constitutes the proceedings of the 17th International Conference and Workshops on Algorithms and Computation, WALCOM 2023, which took place in Hsinchu, Taiwan, in March 2023.The 30 full papers presented together with 2 invited papers were carefully reviewed and selected from 75 submissions. They cover topics such as: computational geometry; string algorithm; optimization; graph algorithm; approximation algorithm; and parameterized complexity.