Angophora leiocarpa, commonly known as rusty gum,[2] is a species of small to medium-sized tree that is endemic to eastern Australia.

[3][4][5][6] Rusty gum was first formally described in 1986 by Gregory John Leach from an unpublished description by Lawrie Johnson and given the name Angophora costata subsp.

[6][7] In 1988 Kevin Thiele and Pauline Ladiges raised it to species status as Angophora leiocarpa.

[8] The specific epithet leiocarpa is derived from the ancient Greek leios meaning 'smooth' and karpon 'fruit', distinguishing this Angophora from others in the genus.

[6] A 2021 molecular analysis of the genus confirmed it was genetically divergent from the two A. costata subspecies, and in fact showed some hybridization with Angophora floribunda.