Duffie Oak, Historic oak tree in Mobile, Alabama.

The Duffee Oak is a Southern live oak in Mobile, Alabama, with a trunk circumference of 30 feet 11 inches (9.42 m), a height of 48 feet (15 m) and a limb spread of 126 feet (38 m). Its low, wide crown rests on heavy limbs that gave the tree its first name, the Seven Sisters Oak.

Originally called the Seven Sisters Oak for its several large limbs, the tree was later renamed for George A. Duffee, a former mayor of Mobile who lived nearby. Scholars estimate it at about 300 years old, making it the city's oldest living landmark. The National Arborist Association recognized it in 1977, and the Alabama Forestry Commission listed it as a famous and historic tree in 2003.

The tree was first called the Seven Sisters Oak for its several large limbs; it later took the name of George A. Duffee, a former Mobile mayor who lived nearby. The Alabama Forestry Commission listed it as a famous and historic tree in 2003.

The oak stands behind an apartment building in the 1100 block of Caroline Street, in a residential part of Mobile. Visitors reach it on foot from the surrounding streets; there is no dedicated parking or visitor infrastructure at the tree itself.

The branches of this Southern live oak dip down to touch the ground before arching upward again, creating natural spaces and sheltered areas beneath the canopy. This unusual shape makes it easy to experience the tree's massive scale up close.