KUSI-TV, virtual channel 51 (UHF digital channel 18), is an independent television station located in San Diego, California, United States. The station is owned by McKinnon Broadcasting. KUSI maintains studio facilities on Viewridge Avenue (near I-15) in the Kearny Mesa section of San Diego, and its transmitter is located southeast of Spring Valley. Its signal is relayed on low-powered K12PO in Murrieta.