KSAZ-TV (channel 10) is a television station in Phoenix, Arizona, United States. It is owned and operated by the Fox network through its Fox Television Stations division alongside KUTP (channel 45), which airs MyNetworkTV programming. The two stations share studios on West Adams Street in Downtown Phoenix; KSAZ-TV's transmitter is located atop South Mountain.

Channel 10 was the third television station established in the Phoenix area, making its first broadcast on October 24, 1953. It was originally allocated as a shared-time channel to stations run by the owners of Phoenix radio stations KOOL and KOY, though both KOOL-TV and KOY-TV operated from the same building. After a year as an independent, it became Phoenix's original ABC affiliate in early 1954. KOOL-TV bought out KOY-TV later in 1954 and absorbed its staff, becoming a full-time station. After switching affiliations to CBS in 1955, KOOL-TV rose to become Phoenix's highest-rated station under the ownership of Gene Autry and Tom Chauncey. A falling-out between Autry and Chauncey ended with the sale of KOOL-TV to the Gulf United Corporation in 1982; separated from its sister radio properties, channel 10 changed its call sign to KTSP-TV. Initially, the station remained the news leader in Phoenix; however, in the late 1980s and early 1990s, the station lost ground in the news ratings to an ascendant KTVK, which had poached two key KTSP-TV executives as part of a successful effort to turn itself around. Channel 10's ratings decline was not helped by several visible personnel miscues.

In February 1994, KTSP-TV changed its call letters to KSAZ-TV. Three months later, as part of the first act in a national realignment of network affiliations initiated by then-owner New World Communications, the station announced it would switch from CBS to Fox. Phoenix was one of the most affected markets; the timing of affiliation contract expirations led to three changes in four months. KSAZ lost CBS in September 1994 but did not begin airing Fox programming until December. Coinciding with the switch to Fox was a major expansion of the station's news department, including new morning and prime time newscasts. However, the three months of forced independent status and miscalculations around syndicated programming and new competitors caused the station's ratings to fall dramatically, with some newscasts losing half their viewership.

Fox acquired the New World stations in 1996 and steadied the struggling operation, instituting a flashier style to bring it more in line with its target audience. From 1999 to 2021, future Arizona gubernatorial and senatorial candidate Kari Lake was one of the station's main anchors. By 2020, KSAZ-TV produced twelve hours a day on weekdays of local news programming.

While the Federal Communications Commission (FCC) worked its way toward ending a years-long freeze on new television station grants initiated in 1948, it issued a near-final version of the table of allocations for Arizona in 1951 that gave Phoenix channels 4 (changed to 3 the next year), 5 (KPHO-TV, the only pre-freeze station in the state), 8, and 10. KOOL (960 AM), Phoenix's CBS radio affiliate, had previously expressed interest in filing for channel 7 prior to the amended table being released, and on September 27, 1951, it applied for channel 10.

KOOL was not alone in its interest. In July 1952, KOY (550 AM), the home of the Mutual Broadcasting System in Phoenix and one of the oldest stations in the state, filed its own bid. The two bids portended what could have been years of comparative hearings over who got the construction permit. To avoid this, in May 1953, KOOL and KOY struck a deal that would result in both getting construction permits to share time on channel 10. The time-sharing proposal, first used by the FCC in television in grants for channel 10 in Rochester, New York, and suggested to KOOL and KOY by the commission, was approved on May 27, 1953, with KOOL-TV and KOY-TV getting construction permits the same day. Under the proposal, the stations would alternate daytime and evening telecasting.

KOOL was the CBS radio affiliate in Phoenix, and KOOL expressed a desire to similarly align its new television station, but this would not be immediately possible. KPHO-TV, which held both CBS and ABC hookups after KTYL-TV signed on with NBC earlier in May, had just signed a renewal agreement with CBS a month and a half before the construction permits were granted. Even though the two stations would have separate staffs and ownership, much of the physical plant would be shared, including a maximum-power transmitter site on South Mountain. Originally proposing to build television studios behind the KOY radio studios near First Avenue and Roosevelt Street, KOOL and KOY arranged instead in July to buy a former car dealership at Fifth Avenue and Adams Street; KOY wanted to continue using the other site for parking. Studio construction started in August, with KOOL and KOY crews leading the way, and a test pattern went out for the first time on October 19, 1953, ahead of both stations' October 24 launch. The next day, channel 10 carried an opening program featuring KOY and KOOL management, including KOOL majority owner Gene Autry.

As shared-time stations, KOOL-TV and KOY-TV were a conjoined unit: separate staffs, common facilities, and no network affiliation at all. This changed in January 1954, when channel 10 picked up an ABC affiliation; now, each of the three major networks had their own outlet in Phoenix. However, KOY-TV would not last much longer. In March 1954, KOOL reached a deal to buy out KOY's stake in channel 10. KOY general manager Albert D. Johnson believed that the station would do better under one operator instead of two and stated that the goal of the shared-time venture—to avoid lengthy comparative hearings—had been met. The FCC approved of the deal—reported as $400,000 by newspapers and $200,000 to the FCC—on May 5, allowing KOOL-TV to become the sole occupant of channel 10. All staff were retained by the enlarged KOOL-TV. It was the first time any of the post-freeze shared-time arrangements had been wound down.