Intercropping is a traditional agronomic practice, and when properly managed, it can significantly contribute to pest control. The current study investigates the severity of plant damage related to infestation by the cotton aphid, Aphis gossypii Glover (Hemiptera: Heteroptera: Aphididae) and its predation by spotless ladybird beetle, Cycloneda sanguinea (L.) (Coleoptera: Coccinellidae) and green lacewing, Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) and parasitism by Lysiphlebus testaceipes (Cresson) (Hymenoptera: Aphidiidae) in sole cotton plots and in plots of cotton intercropped with fennel. Cotton aphid populations were significantly higher in sole cotton plots than in intercropping plots for plots that were not treated with insecticide. The percentages of losses in cotton seed yield were higher in the sole cotton plots than in the four intercropping systems (one row of cotton for two rows of fennel, one row of cotton for three rows of fennel, two rows of cotton for one row of fennel, and three rows of cotton for two rows of fennel). The losses in cotton seed yield were significantly lower in the intercropping system with three rows of cotton interspersed with two rows of fennel than in the other intercropping systems. Spotless ladybird beetle and green lacewing densities were significantly higher in the intercropping system with three rows of cotton interspersed with two rows of fennel than in the other intercropping systems. These results are of practical significance in designing appropriate strategies for cotton aphid control in cotton-fennel intercropping systems.