Herbs that can be planted with eggplant include basil, dill, and celery. These are all good eggplant companion herbs. Because of the high sunlight and nitrogen requirements, it doesn't play well with most herbs which will melt in direct sunlight for hours a day.
Can I plant tomatoes eggplant and peppers together?
Peppers, both sweet and hot, make good companion plants, as they have the same growing needs and are susceptible to the same pests and diseases. Tomatoes are often used as eggplant companions. Again, be sure not to shade the eggplant. Potatoes and spinach are also said to make great companion plantings too.