It began in 1932 as W3XE, an experimental station owned by Philadelphia's Philco Corporation, at the time and for some decades to come one of the world's largest manufacturers of radio and television sets.

When the station began operations as W3XE, it was based within Philco's production plant, at C and East Tioga streets in North Philadelphia, complete with a small studio and transmitter.

In 1941, it began sharing programs with W2XBS (later WNBT and now WNBC) in New York City, becoming NBC's second television affiliate, and creating a link between the station and the network that would last for 54 years.

[3] The Westinghouse Electric Corporation, owner of Philadelphia's longtime NBC Radio affiliate KYW, purchased WPTZ in 1953 for a then-record price of $8.5 million.

In May 1955, Westinghouse agreed to trade WPTZ and KYW radio to NBC in exchange for WNBK television and WTAM AM-FM in Cleveland, and $3 million in cash compensation.

[8] Shortly after NBC took control of channel 3, the Federal Communications Commission (FCC) collapsed the Lehigh Valley, most of northern Delaware and southern New Jersey (including Atlantic City) into the Philadelphia market.

However, almost immediately after the trade was finalized, Westinghouse complained to the FCC and the United States Department of Justice about NBC's alleged coercion and a lengthy investigation was launched.

[12][13] As regulators sifted through that multi-level transaction, Philco Corporation, the original operators of WPTZ and by this point owned by the Ford Motor Company, interjected itself into the dispute by first protesting the FCC's 1957 renewal of NBC's licenses for the WRCV stations.

Westinghouse had moved the KYW call letters to Cleveland after the swap, and channel 3 became KYW-TV upon the company regaining control of the Philadelphia outlets.

[20] This deal, which was spurred by an affiliation agreement between Fox and New World Communications, did not sit well with Westinghouse, who felt betrayed by ABC after nearly half a century of loyalty.

From 1948 to 1989, through NBC's broadcast contract with Major League Baseball, select Philadelphia Phillies contests were aired on channel 3, which included their victory in the 1980 World Series.

Channel 3's newscasts, anchored by Vince Leonard starting in 1958 (during its stint as NBC-owned WRCV-TV), had long been second behind WCAU-TV, but the new format catapulted KYW-TV to first place.

The station tried to stop the decline by adopting a new format called "Direct Connection", with reporters assigned to "beats" such as medical, consumer, entertainment and gossip, among others.

Having seen its quartet of top-rated anchors move on, KYW-TV attempted a reformat of its newscasts, hiring new talent from outside the Philadelphia market to take center stage.

Despite the presence of personalities such as Maria Shriver, Maury Povich, Ron Hunter, Stan Bohrman, and Patrick Emory, Eyewitness News stayed in the ratings basement.

Additionally, long after 5 p.m. newscasts became standard in major markets, channel 3 scaled back its early-evening news block to a half-hour at 6 p.m. to carry first-run syndicated programs during the entirety of the 5 p.m. hour in September 1992.

On February 2, 2009, KYW began to produce a nightly prime time newscast at 10 p.m. for sister station and then-CW affiliate WPSG, Eyewitness News at 10 on The CW Philly.

[38][39][non-primary source needed] Morning meteorologist Katie Fehlinger left the station on September 17, 2019, after more than eight years to spend more time with her family and pursue other professional ventures.

[41] Bilo announced via social media in December 2022 that she would step down as Chief Meteorologist and scale back her schedule to be able to spend more time with her family.

Bilo then appeared in Abreu's former morning and noon position until March 20, 2023, when she officially announced via social media that she would be permanently in that spot and filling in at other times only if asked to.

Exactly a week later, Grant Gilmore announced in a tweet that he would be leaving Tampa Bay CBS affiliate WTSP and joining KYW as their newest meteorologist.

In January 2008, 6 and 11 p.m. news anchor Alycia Lane was fired weeks after she was arrested in New York City the month prior for hitting a female police officer and calling her a "dyke".

A previous incident in May 2007 saw Lane be penalized after it was learned that she had sent a photo of herself in a bikini via the station's email to her friend, NFL Network anchor Rich Eisen.

[74] On June 30, 2015, station management fired longtime lead anchor Chris May, chief meteorologist Kathy Orr, and sports director Beasley Reece without any advance warning in a move that shocked many viewers.

Jessica Dean, who had joined CBS 3 just two years earlier and anchored alongside May, Orr and Reece, was the only member of their broadcast team to avoid being fired.

The next day, on July 1, it was announced that Ukee Washington would be moved from mornings to weeknights to co-anchor with Dean (marking the second time that Washington would be shifted to anchoring weeknights as he had previously anchored the 5 p.m. newscast with Dawn Stensland), while Kate Bilo would take over Orr's slots and become the station's Chief Meteorologist, with morning meteorologist Katie Fehlinger also reporting for the noon newscast, replacing Bilo.

[78] In January 2021, two high ranking executives within CBS 3's parent company Paramount Global (which at the time was known as ViacomCBS) were placed on administrative leave after an investigation was opened due to an article in the Los Angeles Times revealing that CBS Television Stations president Peter Dunn and senior vice president David Friend (who was also the news director at WCBS-TV) were accused of creating a hostile work environment for other news managers and anchors/reporters at other CBS O&O stations by making several racist, sexist and homophobic remarks and purposefully using unfair tactics to prevent Black journalists from being hired or promoted.

Her replacement Rahel Solomon also found herself in Dunn and Friend's crosshairs when they stated in messages and meetings with Kennedy that she too needed to be let go for bizarre reasons, including that they "didn't like her face".

Shortly thereafter, he filed a claim with the Pennsylvania Human Relations Commission in which he stated that he was fired in retaliation for his agreeing to cooperate with the internal investigation of Dunn and Friend.

[84] The station's signal is multiplexed: Digital subchannel 3.2, branded as CBS Philly Plus, was launched in November 2011 as a 24-hour news channel drawing upon the resources of KYW-TV, KYW radio (1060 AM), WPHT (1210 AM), and WIP (610 AM and 94.1 FM).