Oregon's 12th Senate district

District 12 of the Oregon State Senate comprises parts of Yamhill and Polk counties centered around Dallas, McMinnville, and Newberg. It is composed of Oregon House districts 23 and 24. It is currently represented by Republican Brian Boquist of Dallas.

Election results
District boundaries have changed over time. Therefore, senators before 2021 may not represent the same constituency as today. From 1993 until 2003, the district covered parts Clackamas County; from 2003 until 2013, it shifted to cover rural western Benton, Polk, and Yamhill counties plus a small panhandle in southern Marion County and a small part of Linn County to cover the small town of Jefferson; and from 2013 until 2023, it lost some rural land in western Polk and Yamhill counties while adding parts of southern Washington County stretching north to southern Hillsboro.

The current district was consolidated slightly from its previous iterations, losing all of its land in Benton, Marion, and Washington counties while regaining almost all of Polk and Yamhill counties stretching to their western borders.

The results are as follows: