KDFW (channel 4) is a television station licensed to Dallas, Texas, United States, serving the Dallas–Fort Worth metroplex. It is owned and operated by the Fox network through its Fox Television Stations division alongside KDFI (channel 27), an independent station with MyNetworkTV. The two stations share studios on North Griffin Street in downtown Dallas; KDFW's transmitter is located in Cedar Hill, Texas.

On August 20, 1945, the KRLD Radio Corp.—a subsidiary of the now-defunct Dallas Times Herald newspaper, which was headed at the time by Times Herald Printing Co. president Tom C. Gooch—filed an application with the Federal Communications Commission (FCC) for a license and construction permit to operate a commercial television station on VHF channel 2. On August 22, 1946, one year and two days after it filed for the broadcast license, KRLD Radio Corp. amended its application to instead seek assignment on VHF channel 4. (The VHF channel 2 allocation was later reassigned to Denton as part of the FCC's "Sixth Report and Order" in November 1951; it would eventually be assigned to North Texas Public Broadcasting, which signed on KDTN—now a Daystar owned-and-operated station—over that allocation on September 1, 1988.) The FCC Broadcast Bureau granted the license to the Times Herald on September 13, 1946.

The newspaper chose to assign KRLD-TV for use as the television station's call letters; the base KRLD callsign had been used by the Times Herald-owned radio station on 1080 AM—a combined reference to both Edwin J. Kiest, an original investor and one-time owner of the Times Herald, and KRLD (AM), and the radio station's founding owner, Radio Laboratories of Dallas (which changed its name from Dallas Radio Laboratories as it sought the radio permit upon discovering that the KDRL calls had already been assigned for maritime use)—since it signed on its original 1040 AM frequency in October 1926, and applied to its FM sister on 92.5 (now KZPS) upon its March 1948 sign-on.

The station began test broadcasts on November 21, 1949. Channel 4 officially signed on the air, as KRLD-TV, two weeks later on December 3, 1949, at 12:30 p.m., with a short inaugural program featuring speeches from Gooch and KRLD-AM-TV managing director Clyde Rembert dedicating the station's launch, followed by a broadcast of the CBS game show It Pays to Be Ignorant. The first local program aired on the station that day was a college football game in which the Notre Dame Fighting Irish defeated the Southern Methodist Mustangs, 27–20. (The station was originally scheduled to debut on October 1, later pushed back to November 15.) KRLD-TV was the third television station to sign on in the Dallas–Fort Worth metroplex, following Dallas-based KBTV (channel 8, now WFAA) and Fort Worth-licensed WBAP-TV (channel 5, now KXAS-TV), all signing on within a 15-month timeframe. It was also the fourth Texas-based television station to be granted a license by the FCC (along with WBAP-TV, KBTV and Houston's KLEE-TV [now KPRC-TV]).

Channel 4 originally carried programming from CBS, an affiliation that KRLD-TV inherited through the CBS Radio Network's longtime relationship with KRLD (AM), which became the first radio station in Texas to affiliate with the television network's radio predecessor in 1927 (when the station was transmitting at 1040 AM); it was the first Metroplex-area television station to have maintained a singular network affiliation from its sign-on. The station originally broadcast for 4½ hours each weekday (from 7:30 a.m. to noon) and for four hours per day (from noon to 5 p.m.) on Saturdays and Saturdays. Among the local programs on channel 4 in its early years included O.Kay! Mr. Munn (hosted by an artist drawing visual interpretations of various song lyrics, predating the advent of the music video) and Confessions (a series featuring interviews with incarcerated criminals from the Dallas County Jail revealing why they committed the crimes they were convicted of).

The station initially operated from studio facilities located inside the Adolphus Hotel (between Commerce and Main Streets, north of the Times Herald Building) in downtown Dallas. The building—which also housed KRLD radio's facilities at the time—was used on a temporary basis until a permanent broadcast facility then under construction within the Times Herald's Herald Square building (at 1101 Patterson Street, which has since been demolished and converted into a parking lot) was completed. The tower that transmitted its signal (supporting microwave and remote antennas) was also based on the studio grounds. The station's 586-foot (179 m) transmission tower was located on Griffin Street and San Jacinto Avenue; at the time it was incorrectly designated as the tallest free-standing television transmission tower in the world. While it was among the tallest, taller TV towers had already been erected in Columbus, Ohio; Buffalo, New York; and St. Paul, Minnesota. Nonetheless, the tower provided a signal that spanned approximately 90 miles (145 km) from the site. By 1954, KRLD-TV expanded its broadcast day to an 18-hour daily schedule (running from 6 a.m. to midnight). In May 1955, the station began construction of a new 1,521-foot (464 m)-tall tower in Cedar Hill. At the time of its completion in October 1955, the structure was considered to be the tallest television broadcast tower in the world (once KRLD-TV moved its transmitter to the Cedar Hill tower in early 1956, the original Griffin Street transmitter remained in use as an auxiliary facility until it was disassembled in 1984; the antenna on which it was installed was torn down in 1995, to reduce the load on the tower).

KRLD-TV served as the home base for CBS' network coverage of the assassination of President John F. Kennedy on November 22, 1963, when suspect Lee Harvey Oswald (from an upper-floor window at the Texas School Book Depository) shot his rifle at sniper range at the Presidential motorcade carrying Kennedy and Texas Governor John Connally as it had turned onto Elm Street. Eddie Barker, who was KRLD-TV's news director at the time and had been with the station since it signed on fourteen years earlier as one of the original members of its news department staff, was the first person to announce Kennedy's death on television, relaying a message from an official at Parkland Hospital that Kennedy had succumbed from the gunshot wound as doctors conducted emergency surgery. Because of a local press pool arrangement that was put in place that morning to cover Kennedy's speech at the Trade Mart downtown, Barker's scoop appeared live simultaneously on CBS, which had sent correspondent Dan Rather to report from Dealey Plaza, and ABC. Two days later, a KRLD-TV field crew captured footage of Oswald's assassination by nightclub owner Jack Ruby as officers were transferring the former in handcuffs out of the Dallas Police Department's downtown precinct.

CBS also maintained an arrangement with Channel 4 to use the station's remote unit to transmit live programming broadcast by the network during the 1960s and 1970s; in particular, the remote transmission truck was used to relay color broadcasts of CBS' NFL and college football game telecasts held in Texas. In 1964, KRLD-TV moved its operations from the Times Herald's Patterson Street offices into the station's current, purpose-built studio facility at 400 North Griffin Street (across the street from the former building, at the intersection of Griffin and San Jacinto). In 1968, the station's Cedar Hill transmitter site was struck by a helicopter, causing substantial damage to the tower.