Field trials were conducted at two locations in the South Omo zone to evaluate the effect of neem oil concentration and its application frequencies on reducing fall armyworm damage on maize. The experiment was laid out in a randomized complete block design comprising five concentrations of neem oil (NO) and two frequencies and replicated three times. Percentage of infested plants, leaf damage, and maize yield were collected and analyzed. Concentrations and intervals have shown a significant effect on variables such as the percentage of infested plants, leaf damage, the number of cobs per plant, cob length, and grain yield. The lowest rate of plant infestation and leaf damage was recorded from the weekly application of NO 3% next to the application of standard insecticide. Similarly, the highest grain yield was obtained from the weekly application of 3% NO, comparable with the standard insecticide-diazinon. Therefore, due to damage reduction and the highest yield obtained from weekly application of 3% NO, it was recommended as an alternative option to synthetic chemicals. Integration of recommended neem oil concentration with other options is important for fall armyworm management in the maize production system of the study area.