KMIZ (channel 17) is a television station licensed to Columbia, Missouri, United States, serving the Columbia–Jefferson City market as an affiliate of ABC and MyNetworkTV. It is owned by the News-Press & Gazette Company alongside Fox affiliate KQFX-LD (channel 22, also licensed to Columbia); the stations together are branded as the "Networks of Mid-Missouri". The two stations share studios on the East Business Loop 70 in Columbia; KMIZ's transmitter is located west of Jamestown.

Channel 17 in Columbia began broadcasting as KCBJ-TV on December 5, 1971. It brought a full-time ABC affiliate to Mid-Missouri; the network's programming had previously been split between the market's two other major commercial stations. KCBJ-TV was built by Richard Koenig, a St. Louis–based engineer. It struggled in its early years with its ultra high frequency (UHF) signal, the first in the market; entrenched and established competition; and lack of financial resources to invest in local programming and technical improvements. In 1979, Koenig agreed to sell the station to the Wooster Republican Printing Company, but the deal turned sour, and the prospective buyers sued for breach of contract. Litigation in that case was still pending when an ascendant ABC switched its affiliation to KOMU-TV (channel 8) in 1982, leaving KCBJ-TV to take over KOMU's former NBC affiliation.

Koenig sold KCBJ-TV to Stauffer Communications, which took control in January 1985. With NBC rising in the ratings, it poached KOMU-TV from ABC, leading to a switch of network affiliations again that December. To coincide with the new affiliation and Stauffer's investment in a new image and improved news coverage, the station changed its call sign to KMIZ. Under Benedek Broadcasting ownership, KMIZ purchased two low-power stations to start the area's Fox affiliate, a predecessor of KQFX-LD. News-Press & Gazette Company acquired the stations from JW Broadcasting in 2012.

In September 1969, Jeffco Television Corporation, associated with station WJJY-TV in Jacksonville, Illinois, applied to the Federal Communications Commission (FCC) for permission to build a station on ultra high frequency (UHF) channel 17 in Columbia. At the time, Mid-Missouri had no full-time affiliate of ABC; its programs were split between primary NBC affiliate KOMU-TV (channel 8) and primary CBS affiliate KRCG (channel 13). In November, Channel Seventeen, Inc., headed by St. Louis engineer Richard Koenig, also applied for the channel. The two applications were designated by the commission for comparative hearing, but Jeffco dropped out due to problems at its station in Illinois, allowing Channel Seventeen to receive the construction permit on August 28, 1970.

KCBJ-TV began broadcasting on December 5, 1971, as a full-time ABC affiliate. It broadcast from a tower at Jamestown, Missouri, 17 miles (27 km) southwest of Columbia. The station's early months were pocked with technical issues; it was the only local station with a studio and transmitter at separate sites. Moreover, many older television sets still in use were not UHF-capable. Unable to afford a direct microwave feed, Koenig had his engineers switch to and from the signal of KMTC-TV in Springfield—which, in turn, picked up the signal off-air from KODE-TV in Joplin. If a network program was preempted in either of those cities, KCBJ-TV could not show it; occasionally, weather warnings and other material from the Springfield area appeared on channel 17 as well. In its first three and a half years of operation, the station never once made a profit and, as a result, could not afford the expenditures necessary to improve the quality of its incoming network feed. In the ratings, KCBJ-TV struggled against KOMU and KRCG, which had been in the market nearly 20 years when channel 17 signed on and were better-funded stations with stronger local news presences. Koenig became aggressive in his efforts to defend channel 17 from competition. He unsuccessfully argued that KOMU-TV, a commercial station owned by the University of Missouri (MU) and the more successful of Columbia's two local stations, should be forced to become non-commercial and a new private commercial station on the UHF band opened to provide NBC programming. He successfully led the FCC to deny a tower upgrade for KTVO, an ABC affiliate in Kirksville, that threatened to take viewers away from his station in such cities as Moberly, Mexico, and Centralia. He fought the introduction of cable television to Columbia, winning network non-duplication protection so that channel 17 was the only source for ABC network programs on the system—even though the CBS and NBC affiliates did not receive the same perk. As the decade went on, channel 17 became more reliable and obtained its own microwave link to improve signal quality for ABC programming. In 1978, it acquired its present studio facilities from Columbia College, which had used the site to house its extended studies program; this enabled channel 17 to triple its office space and vacate its site in the Tiger Hotel downtown, where it had utilized a portion of the hotel's parking garage.

Koenig agreed in August 1979 to sell KCBJ-TV to the Wooster Republican Printing Company of Wooster, Ohio, controlled by the Dix family. The acquisition of channel 17 would have marked the return of the Dix family to television after their sale years prior of WTRF-TV in Wheeling, West Virginia. Two months later, the Dix family sued, claiming Koenig had breached the sale contract; Koenig replied by declaring that there never was a valid contract. In 1981, the Dix family won the initial lawsuit and a court order forcing Koenig to sell the station to them. Koenig appealed the ruling; federal judge Scott Olin Wright, a former lawyer in Columbia, ordered the station to be transferred to a receiver during the process, but Koenig refused, claiming Wright held a grudge against KCBJ-TV from an earlier legal contact when the station started and that a short-form transfer of control was not appropriate for the process.

As the appeals continued in the breach of contract case, ABC sought to move to the higher-rated KOMU-TV. In the late 1970s, ABC became the number-one network and began seeking upgrades in its affiliate base, primarily at the expense of NBC. It contacted KOMU-TV, the number-one station in Mid-Missouri, in 1979; that was the year NBC hired Fred Silverman, and KOMU instead renewed with NBC in hopes that Silverman could turn around the network's low ratings. This did not materialize, and the station instead agreed to switch in 1982. While it was logical that KCBJ-TV, the local station without a network affiliation, and NBC, the network needing a station, would connect, the ongoing ownership dispute complicated matters because the network received affiliation pitches from the Koenigs and the Dix family. The switch was set for July 12, but Wright issued a temporary restraining order to prevent ABC from moving. KOMU's ABC switch was then set for August 8, though no NBC deal was in place for channel 17 until late July. The sale to Wooster Republican Printing Company fell through by February 1983.

In October 1984, Stauffer Communications agreed to purchase KCBJ-TV from the Koenig family, assuming control in January 1985. The company's first priority was to revamp the station's neglected and little-watched news operation, described by the Columbia Daily Tribune as "laughable at best" and by station manager Rush Evans as a "cursory programming service". It was a distant third behind KOMU and KRCG in the ratings, only attracting three percent of the audience. The newscasts finally had two cameras instead of one, and the news staff was increased from five employees to thirteen. At the same time, the fortunes of NBC turned; the network was in the lead nationally, and KCBJ was the number-one station in prime time. Citing its disappointment with revenues under ABC, KOMU announced it would return to NBC. It was not alone; other recent converts from NBC to ABC were beginning to return to the network, including stations in Temple, Texas, and Savannah, Georgia.