Big Branch is a 3.59 mi (5.78 km) long tributary of Crabtree Creek in Wake County, North Carolina,[4] and is classed as a 2nd order stream on the EPA waters geoviewer site.

[3] Big Branch rises in northern Raleigh, North Carolina, then flows south to meet Crabtree Creek across from Kiwanis Park.

Big Branch drains 3.98 square miles (10.3 km2) of area.

The upper part of the watershed is underlaid by Falls Leucogneiss.

The middle and lower watershed is underlaid by Raleigh Gneiss geology.