The area code 510 is located in Alameda, California.
Area code 510 serves the East Bay along the San Francisco Bay, covering western Alameda County and parts of western Contra Costa County. Centered on the city of Alameda, California, this area code stretches along the I-880 and I-80 corridors and anchors key hubs for education, shipping, and culture. It includes major landmarks like the Port of Oakland, Oakland International Airport (OAK), Lake Merritt, and the UC Berkeley campus. The region operates on Pacific Time and features dense urban neighborhoods, university zones, and waterfront districts.
Introduced in 1991 after a split from 415, 510 later shed its inland communities to 925 in 1998 and gained an overlay with area code 341 in 2019. Today, 510/341 phone numbers are assigned across both landlines and mobile phones, and ten-digit dialing is standard throughout the service area. This East Bay area code is known for diverse communities, a strong transit network, and a mix of tech, education, and maritime jobs. If you see a 510 number, it typically points to the inner East Bay, especially around Alameda and Oakland.
Major cities in area code 510 include:
From the Oakland Coliseum and Jack London Square to research centers like Lawrence Berkeley National Laboratory, the 510 area blends history and innovation. UC Berkeley stands as one of the world’s leading public universities, and the Port of Oakland remains a major West Coast gateway for goods. The 341 overlay means new phone numbers may use 341 while serving the same communities as 510, keeping local calling consistent across the East Bay. Together, 510 and 341 link some of Northern California’s most recognizable neighborhoods and landmarks.
“Created in 1991, split in 1998, and overlaid in 2019.” — Sources: NANPA; California Public Utilities Commission (CPUC)