The 78th Oregon Legislative Assembly convened beginning on February 2, 2015, for the first of its two regular sessions.

[1] Oregon was the only state where Democrats made net gains in both legislative chambers in the 2014 midterm elections.

[2][3] Based on the results of the 2014 elections, the Oregon State Senate is composed of 18 Democrats and 12 Republicans.

Senate President: Peter Courtney (D–11 Salem) President Pro Tem: Ginny Burdick (D–18 Portland) Majority Leader: Diane Rosenbaum (D–21 Portland) Minority Leader: Ted Ferrioli (R–30 John Day) Based on the results of the 2014 elections, the Oregon House of Representatives is composed of 35 Democrats and 25 Republicans.

Democrats won District 20, which was previously Republican-held, while Republicans picked up no additional seats.