Seven Sisters Oak, Live oak tree in Mandeville, Louisiana, US

Seven Sisters Oak is a southern live oak in Mandeville, Louisiana, registered as the largest live oak in the Live Oak Society. In 2016 its trunk measured 39.6 feet (12.1 m) in girth at 1.6 feet (0.49 m) above the ground and the tree stood 57 feet (17 m) tall; by 2018 its limb spread exceeded 153 feet (47 m).

The tree was first registered in the Live Oak Society as "Doby's Seven Sisters" (No. 200), because the Doby family owned the land and Mrs. Doby was one of seven sisters. It was later renamed Seven Sisters Oak and re-registered as member No. 697. A 1976 inspection by professional foresters settled the question of whether it was one tree or several grown together, finding a single root system.

The tree holds the title of president within the Live Oak Society, an organization dedicated to preserving old oaks. This role passed to the Seven Sisters after the Locke Breaux Oak was lost.

The tree stands on private property but can be viewed from outside. Visitors wishing to take photographs should seek permission from the owners beforehand.

The original registration name, "Doby's Seven Sisters" (No. 200), came from the Doby family who owned the land, and Mrs. Doby was one of seven sisters; the tree was later re-registered as No. 697. Foresters who inspected it in 1976 settled a dispute by confirming a single root system, not several trees grown together.