Islanding detection is becoming a vital aspect of the power system as the penetration of distributed generators in the utility power system continues to grow. If the distribution generation (DG) capacity matches the connected feeder load the islanding detection takes longer due to the minimal power imbalance between the DG and the utilities prior to islanding event. This research work proposes a slip and acceleration angle-based islanding detection algorithm using phasor measurement unit (PMU) voltage angle data. Specifically, this research utilizes the grid and DG bus voltage angles in the form of their slip and acceleration angle parameters. This research work presents the performance results of the proposed islanding detection algorithm for the under frequency, over frequency, and match frequency islanding conditions. The proposed algorithm is developed using IEEE 30 bus system and validate with the actual Utility Kerteh system (located in Terengganu, Malaysia) based on simulated PMU voltage angle data for 8 different island and non-island cases. Notably, the proposed algorithm shows that it can detect all islanding conditions of the Utility Kerteh system at 20ms, which means it requires only one cycle duration after island incepts in the network.