California's 25th State Senate district is one of 40 California State Senate districts. It is currently represented by Democrat Anthony Portantino of La Cañada Flintridge.
The district encompasses most of the San Gabriel Mountains and its adjacent San Gabriel Valley foothill communities. It stretches from the eastern San Fernando Valley in the west to the far western Inland Empire in the east. Most of the district's population is in the western half of the district, anchored by Glendale and Pasadena.
Due to redistricting, the 25th district has been moved around different parts of the state. The current iteration resulted from the 2011 redistricting by the California Citizens Redistricting Commission.