The Millicoma River is a coast stream, about 8.5 miles (13.7 km) long, east of Coos Bay in the U.S. state of Oregon.

The Millicoma meanders generally southwest, receiving Woodruff Creek from the left slightly downstream from Allegany.

Deton Creek enters from the right at Rooke Higgins County Park near river mile (RM) 3.5 or river kilometer (RK) 5.6.

It also supports runs of Coho salmon, but fishing for them in the Millicoma is not allowed.

Rooke Higgins County Park has a boat launch as does Doras Ramp, near the mouth.