Dobbins is north of Oregon House and south of Bullards Bar Dam.

According to the United States Census Bureau, the CDP covers an area of 7.8 square miles (20.3 km2), 99.08% of it land and 0.92% of it water.

The town was settled in 1849, and named for William M. and Mark D. Dobbins, early settlers.

There were stage station stops, for teamsters' and their wagons, at what was known as Scott Ranch (three miles below Dobbins- Marysville Rd).

The first post office was established in 1851 under the name Dobbins Ranche, which was closed in 1854.

There were 319 housing units at an average density of 40.8 per square mile (15.8/km2), of which 174 (67.7%) were owner-occupied, and 83 (32.3%) were occupied by renters.