This document presents a study that compares the performance of various decision tree algorithms (J48, Hoeffding Tree, Random Forest, Random Tree, REPTree, Decision Stump) on student academic performance data. The study uses educational datasets containing student marks and percentages to classify students into performance grades (A,B,C) and predict their marks in future semesters. The decision tree algorithms are implemented on the datasets using the WEKA data mining tool. The algorithms are evaluated and compared based on accuracy in classifying students and predicting future marks. The results show that J48, Random Forest and Random Tree algorithms achieved 100% accuracy on the training and some test datasets, performing the best among the algorithms evaluated.