Juglandinae is a subtribe of the Juglandeae tribe, of the Juglandoideae subfamily, in the Juglandaceae family. Walnut tree species make up the genus Juglans, which belongs to the subtribe Juglandinae.

Walnut trees are any species of tree in the plant genus Juglans, the type genus of the family Juglandaceae, the seeds of which are referred to as walnuts. All species are deciduous trees, 10–40 metres