The 23rd State Senate District covers portions of Riverside, San Bernardino, and Los Angeles Counties. The district includes all or portions of the following communities: Banning, Beaumont, Big Bear City, Big Bear Lake, Bloomington, Cedar Glen, Calimesa, Cherry Valley, Crestline, Homeland, Hemet, Highland, Lake Arrowhead, Loma Linda, Menifee, Mentone, Nuevo, Phelan, Pinon Hills, Rancho Cucamonga, Redlands, Rialto, San Bernardino, San Jacinto, Wrightwood, and Yucaipa.
- Red: Senate District 23 map
- Green: Additional areas assigned to represent until 2024.