Curtin is an unincorporated community in Douglas County, Oregon, United States. It is on Interstate 5 and the former Southern Pacific railroad line about seven miles northeast of Drain. The community was named for Daniel Curtin, who was a local sawmill owner in the 1890s. Curtin post office was established in May 1908. Its ZIP code was 97428, but as of 2009, Curtin post office had closed out to Cottage Grove.