District 30 of the Oregon State Senate comprises all of Baker, Crook, Grant, Harney, Lake, and Malheur counties, as well as parts of Deschutes and Jefferson counties. The district is composed of Oregon House districts 59 and 60 and is the largest state Senate district in Oregon. It is currently represented by Republican Lynn Findley of Vale.

District boundaries have changed over time. Therefore, senators before 2013 may not represent the same constituency as today. From 1993 until 2003, it covered a slightly different area in eastern Oregon; from 2003 until 2013, it extended to cover Gilliam, Jefferson, Sherman, Wasco, and Wheeler counties and parts of Deschutes and Lake counties; and from 2013 until 2023, it lost all of these gains except western Wasco County, northern Deschutes County, and Jefferson County.

The current district is more compact and adds all of Crook and Lake counties, which have historically been a part of other districts, while losing parts of northern Jefferson County and northern Deschutes County as well as all of Wasco and Wheeler counties.

The results are as follows:^[1]