Oregon Route 42 is an Oregon state highway which runs between U.S. Route 101 on the Oregon Coast, near Coos Bay, and Green, a few miles south of Roseburg on Interstate 5. It is known as the Coos Bay-Roseburg Highway No. 35 (see Oregon highways and routes). At Coquille, there is a split in the route, as Oregon Route 42S heads southwest toward Bandon. The largest towns on the route are Winston, Coquille, Myrtle Point, and the unincorporated community of Green. Oregon Route 42 is the southernmost reliable link between the Oregon Coast and the Interstate 5 corridor, although the notorious Bear Camp Road is farther south.

The section of Oregon Route 42 between its junction with U.S. Route 101 south of Coos Bay and its junction with Oregon Route 42S in Coquille was once a part of U.S. Route 101. When U.S. Route 101 was moved to an alignment closer to the ocean, Oregon Route 42 was extended along the northernmost section and Oregon Route 42S was created along the southernmost section.

Oregon Route 42S is an Oregon state highway which is located entirely within Coos County. It runs between U.S. Route 101 at Bandon and Coquille on Oregon Route 42. It is known as the Coquille-Bandon Highway No. 244 (see Oregon highways and routes). It serves as an important link between Interstate 5 and the southern Oregon Coast, as it forms the southernmost all-season connection between the two in Oregon. Oregon Route 42S used to be a part of U.S. Route 101, and was created when US 101 was realigned closer to the ocean.