South Carolina Highway 641 (SC 641) is a 21.560-mile (34.697 km) primary state highway in the U.S. state of South Carolina.

It also serves access to Rivers Bridge State Park.

[4] The highway was established around 1932 as a new primary spur of SC 64 to SC 36 (today US 601).

In 1942, its alignment was straightened, leaving Rivers Bridge Road (S-5-31/S-15-37).

In 1952, it was extended west again to the southern boundary of the Savannah River Plant, replacing part of SC 28; reaching its apex of over 44 miles (71 km) long.