Originally, the station was assigned call letters KQXI; calls were changed to KNTV in May 1955, and signed on the air on September 12 of same year. At that time, it was operating as an independent station covering the entire north-central California coast from Monterey to San Francisco on VHF channel 11. It was the first television station in San Jose and was originally operated by Standard Radio and Television Corporation, which was owned by Allen T. Gilliland.
Due to channel 11's transmitter and antenna location, its signal could be received fairly well in the nearby areas of Monterey and Salinas; the transmitter was located approximately halfway between San Jose and Monterey. Taking advantage of this, KNTV sought and was granted the ABC affiliation for the Monterey Bay area in 1960, on the condition that the station reduced its transmitter power so as not to overlap with network-owned KGO-TV's signal. Previously, all three networks had been shoehorned onto Salinas-based KSBW-TV (channel 8). KNTV, therefore, became one of the few stations located outside the market it served.
In 1999, KGO-TV agreed to pay Granite a substantial fee to stop channel 11 from running ABC programming once the station's affiliation contract expired. ABC's corporate parent, The Walt Disney Company, saw the need to expand channel 7's exclusive advertising market share into San Jose for this reason, and it felt that KNTV was taking away from the share. Channel 11 switched its affiliation from ABC to The WB on July 3, 2000, becoming one of two affiliates of that network in the San Francisco Bay Area, alongside with then-sister station KBWB (now known as KOFY-TV), taking place of network-owned KGO-TV.
At 11:35 pm Pacific Standard Time on December 31, 2001, KNTV became an NBC affiliate after a disagreement over reverse compensation to carry NBC programming led KRON-TV to end its affiliation with NBC after 52 years, becoming an independent station. Later, on April 30, Granite sold KNTV to the network (the WB affiliation remained with channel 20) and utilized its standardized graphics package. NBC had just purchased Telemundo, which owns nearby station KSTS (UHF channel 48), and NBC wanted a duopoly in the Bay Area. The name "NBC 3" refers to the station's cable channel placement.
NBC 3 was rebranded as NBC 11 in September 2002 due to possible confusion with Sacramento-licensed fellow affiliate KCRA-TV, which broadcasts on VHF channel 3 whereas KNTV broadcasted on VHF channel 11.
In 2008, KNTV changed its on-air branding from "NBC 11" to "NBC Bay Area", related to the San Francisco Bay Area from San Jose.