California's 38th senatorial district is one of 40 California State Senate districts. It is currently represented by of .
The district encompasses the coastal North County region of San Diego County, including the communities of La Jolla, Del Mar, Solana Beach, Cardiff, Rancho Santa Fe, Encinitas, Carlsbad, Vista, Oceanside, San Luis Rey, and Camp Pendleton Marine Corps Base; along with the southern edge of Orange County, including San Clemente, San Juan Capistrano, Ladera Ranch, Las Flores, and Rancho Santa Margarita.
Due to redistricting, the 38th district has been moved around different parts of the state. The current iteration resulted from the 2021 redistricting by the California Citizens Redistricting Commission.