KOB-TV started operations on November 29, 1948, after Albuquerque Journal owner and publisher Tom Pepperday won a television license on his second try.

Later, in May 1952, the KOB stations were purchased by magazine publisher Time-Life (later Time Inc.) and former Federal Communications Commission (FCC) chairman Wayne Coy.

[2] In 1953, two new TV stations signed on within a week—KGGM-TV (channel 13, now KRQE), which affiliated with CBS, followed by KOAT, which took ABC; DuMont shut down in 1956.

When KOAT's top anchorman, Dick Knipfing, was fired on June 4, 1979, KOB hired him to anchor their newscasts.

Although KOAT sued to keep Knipfing off the air until the following year,[4] an opinion from the United States District Court allowed the anchorman to proceed with his plans to begin anchoring channel 4 on August 1,[5] creating the first big-dollar anchor in Albuquerque, and allowing him to stand out in the industry as the "anchorman wars" moved to smaller markets.

KOB produced an hour-long nightly newscast for Albuquerque's then-Fox affiliate, KASA-TV, from November 2000 through September 14, 2006, called Fox 2 News at Nine.

[6] This marked the end of a transitional services agreement KASA-TV had with Gray Television, which had purchased its former Ramar Communications-owned sister stations in Lubbock (including KJTV-TV), to continue news production in the short term.

[7] The station's signal is multiplexed: In September 2006, KOB-TV began broadcasting NBC WeatherPlus on digital subchannel 4.2, at first inserting its Doppler weather radar during time reserved for local segments.

Weekly E/I programming required of broadcast television stations by the FCC came from NASA TV on weekend mornings.

As part of the SAFER Act,[15] KOB-TV kept its analog signal on the air until June 30 to inform viewers of the digital television transition through a loop of public service announcements from the National Association of Broadcasters.