Autumn olive is a medium to large, multistemmed shrub, often reaching heights of 20 feet. Sometimes there are a few thorns on the twigs.
The leaves, borne alternately on the stems, are generally oval, 1–3 inches long, wavy, and lack teeth. The upper surface of leaves is dark green to grayish green, while the lower surface is covered with silvery white scales, a conspicuous characteristic that can be seen from a distance.
Flowers are small, light yellow, fragrant, borne in clusters along twigs, and bloom in late April and May. The outsides of the flowers have small, silvery scales.
Fruits are small (less than ¼ inch), fleshy, juicy, start as yellowish and ripen from pink to red, with speckles. They are finely dotted with pale scales and are produced in abundance each year.
Similar species: Russian olive (E. angustifolia) has both sides of leaves (at least when the leaves are young) covered with only silvery scales, making top and bottom sides look silvery, while autumn olive has few scales on the upper surface, making it look green, and the lower surface, though covered with mostly silvery scales, also always has a few rusty scales interspersed with them.