This book constitutes the proceedings of the 21st International Conference on Data Science, ICDATA 2025, and the 24th International Conference on Information and Knowledge Engineering, IKE 2025. They were held as part of the 2025 World Congress in Computer Science, Computer Engineering, and Applied Computing, CSCE 2025, which took place in Las Vegas, NV, USA, during July 21-24, 2025. The ICDATA 2025 Conference received a total of 182 submissions, of which 44 papers were accepted; 31 of these are included in this book. The IKE 2025 Conference received 97 submissions, of which 18 papers were accepted; 8 of these were selected for inclusion in this book. This volume includes 39 of the accepted papers from ICDATA 2025 and IKE 2025. The papers were organized in topical sections as follows: Data Science, Artificial Intelligence, and Applications; Data Mining and Applications - Signal Processing, Security, BPC, and Imaging Science; Data Science, Algorithms, and Novel Applications; 24th International Conference on Information and Knowledge Engineering, IKE 2025; and Poster Research Papers.