South Brother is a mountain located in Piscataquis County, Maine, in Baxter State Park.

The northeast and southeast sides of South Brother drain into a swampy area called "The Klondike", then into Wassataquoik Stream, and the East Branch of the Penobscot River.

The west sides of South Brother drain into Roaring Brook, Nesowadnehunk Stream, and the West Branch of the Penobscot River.

The Appalachian Trail, a 2,170-mile (3,490 km) National Scenic Trail from Georgia to Maine, reaches it northern terminus, Mount Katahdin, 5 miles (8 km) to the southeast of The Brothers.

This Maine state location article is a stub.