As of the 2020 redistricting, California's 38th congressional district is located in Southern California. It is entirely within western Orange County.
Orange County is split between this district, the 40th district, the 45th district, and the 47th district. The 46th and 40th are partitioned by E La Palma Ave, E Jackson Ave, E Frontera St, Santa Ana River, Riverside Freeway, Costa Mesa Freeway, N Tustin St, E Meats Ave, N Orange Olive Rd, Garden Grove Freeway, 16909 Donwest-16791 E Main St, E Chestnut Ave, 16282 E Main St-717 S Lyon St, E McFadden Ave, Warner Ave, and Red Hill Ave.
The 46th, 45th, and 47th are partitioned by Red Hill Ave, E Alton Parkway, Costa Mesa Freeway, Sunflower Ave, Harbor Blvd, MacArthur Blvd, Santa Ana River, W Lehnhardt Ave, Gloxinia Ave, Lilac Way, Edinger Ave, Pebble Ct, 10744 W Lehnhardt Ave-10726 Kedge Ave, 724 S Sail St-5641 W Barbette Ave-407 S Starboard St, Starboard St/S Cooper St, Taft St, Hazard Ave, N Euclid St, Westminster Ave, Clinton St, 14300 Clinton St-1001 Mar Les Dr, Mar Les Dr, 2729 Huckleberry Rd, N Fairview St, Fairview St, 13462 Garden Grove Blvd-13252 Marty Ln, Townley St/Siemon Ave, W Garden Grove Blvd, S Lewis St, W Chapman Ave, E Simmons Ave, S Haster St, Ascot Dr, W Orangewood Ave, S 9th St, 2209 S Waverly Dr-11751 S Waverly Dr, Euclid St, Haven Ln, W Dudley Ave, S Euclid St, Katella Ave, Dale St, Rancho Alamitos High School, Orangewood Ave, Barber City Channel, Arrowhead St, Del Rey Dr, Westcliff Dr, Lampson Ave, Fern St, Garden Glove Blvd, Union Pacific Railroad, 7772 W Chapman Ave-Bently Ave, Highway 39, Western Ave, Stanton Storm Channel, Knott Ave, 6970 Via Kannela-6555 Katella Ave, Cerritos Ave, 10490 Carlotta Ave-Ball Rd, John Beat Park, S Knott Ave, Solano Dr, Monterra Way, Campesina Dr, Holder Elementary School, W Orange Ave, 6698 Via Riverside Way-Orangeview Junior High School, W Lincoln Ave, 195 N Western Ave-298 N Western Ave, 3181 W Coolidge Ave-405 N Dale St, W Crescent Ave, N La Reina St, W La Palma Ave, Boisseranc Park, I-5 HOV Lane, Orangethorpe Ave, Fullerton Creek, Whitaker St, Commonwealth Ave, Los Angeles County Metro, W Malvern Ave, W Chapman Ave, E Chapman Ave, S Placentia Ave, Kimberly Ave, E Orangethorpe Ave, and 2500 E Terrace St-Highway 57.