Sprinter (stylized in all caps) is a hybrid rail (light rail with some features similar to commuter rail) service operating in the North County area of San Diego County between the cities of Escondido and Oceanside, California, United States. The service uses the 22-mile (35 km) Escondido Subdivision of the San Diego Northern Railroad. Station platforms were constructed for the line's fifteen stations serving the cities of Oceanside, Vista, San Marcos, and Escondido. The line provides service to California State University, San Marcos and Palomar College. Sprinter service operates every 30 minutes and is targeted towards students and commuters.
Sprinter is operated by the North County Transit District, the area's public transit agency. The agency also operates the Coaster commuter rail service and the Breeze transit bus services. At Oceanside Transit Center, Sprinter connects to three commuter rail services (Coaster and the Metrolink Orange County and Inland Empire–Orange County lines), as well as to Amtrak's Pacific Surfliner inter-city rail service.
Just after the COVID-19 pandemic, ridership for Sprinter declined by 46 percent (fiscal year 2020-21), according to The San Diego Union-Tribune. During the pandemic, it is assumed ridership was dramatically reduced as many worked or went to school from home.