Eucalyptus sessilis is a mallee tree that is native to the Northern Territory and central areas along the border of Western Australia. The tree has a spreading and straggly habit, is between 2–4 metres high, and occurs on stony slopes. Its bark is smooth and peels away in strips when shed. The flowering period is between April to July, the stamens that appear from the capsule are a yellow-cream colour. The species was first described in 1934. A common name for this tree is the Finke River (or River) mallee.