Black walnut may refer to:

Trees

Family Juglandaceae, genus Juglans sect. Rhysocaryon:

• Juglans nigra, the eastern black walnut, a species of flowering tree native to eastern North America.
• Juglans californica, California black walnut or Southern California black walnut.
• Juglans hindsii, the Northern California walnut or Hinds' black walnut.
• Juglans major, Arizona black walnut.
• Juglans microcarpa, Texas black walnut or little black walnut.
• Juglans venezuelensis, a species of black walnut endemic to Venezuela.

Other:

• Endiandra globosa, an unrelated species of Australian rainforest tree from the family Lauraceae.
• Endiandra palmerstonii, another species of Australian rainforest tree from the family Lauraceae.

Places

• Black Walnut, Missouri, a community in the United States
• Black Walnut (Clover, Virginia), a historic house in Virginia