WHYY-TV (channel 12) is a television station licensed to Wilmington, Delaware, United States, serving as the primary PBS member station for the Philadelphia area. It is owned by WHYY, Inc., alongside NPR member WHYY-FM (90.9). WHYY-TV and WHYY-FM share studios and offices on Independence Mall in Center City, Philadelphia, with an additional office in Wilmington; through a channel sharing agreement with WMCN-TV (channel 44), the two stations transmit using WHYY-TV's spectrum from an antenna in Philadelphia's Roxborough section.

WHYY-TV is one of four PBS member stations serving the Philadelphia market, alongside Philadelphia-licensed WPPT (channel 35), Allentown-based WLVT-TV (channel 39), and NJ PBS (WNJS, channel 23, and WNJT, channel 52). In southern Delaware and on the Delmarva Peninsula, WHYY-TV is seen on WDPB (channel 64), a full-time rebroadcaster in Seaford, Delaware.

WHYY-TV was established in 1957 on channel 35 in Philadelphia as the first educational TV station in the city. Seeking to expand its coverage area, it successfully filed to use channel 12 in Wilmington, which was left vacant after the closing of a commercial station, and moved its primary programming there in 1963. It also opened a Wilmington studio and began producing Delaware-oriented public affairs programming.

In May 1951, Philadelphia's Board of Education first considered the idea of asking for an educational television channel, either Philadelphia's 35 in the newly created UHF band or the channel 12 allocation at Wilmington, for use by the city schools and other organizations. A $150,000 grant from the Ford Foundation was received in 1953, when the Delaware Valley Educational Television Corporation was chartered and filed for channel 35. A year later, the Philadelphia Educational Radio Corporation, a consortium of schools and colleges, launched WHYY (90.9 FM), the city's first noncommercial radio service, on December 15, 1954.

With WHYY radio in operation, the focus shifted to giving birth to WHYY television. After the organization changed its name to the Metropolitan Philadelphia Educational Radio and Television Corporation, it received a construction permit in March 1956 for a station on UHF channel 35, the designated educational television channel for the city. That April, WHYY negotiated a five-year lease of the former WCAU-TV studios at 1622 Chestnut Street. Plans called for a weekly output of 25 hours of programming. The station appeared ready to go on November 26, 1956. Twelve city schools were being equipped with UHF-capable sets to receive the programs; a two-page feature entitled "This Is WHYY" ran in a late October edition of The Philadelphia Inquirer Magazine; and test patterns were being broadcast. However, an unexpected snag emerged between station management and the school board. It had committed $100,000 to finance the station but instead opted to give only $75,000, diverting the remainder to a management study of the new outlet by a New York firm. The school board wanted control to be based on financial contributions, which would have given it more power in station decision-making, and there were also concerns that the UHF station would suffer from the inability of all television sets to tune that band (as television sets were not required to include UHF tuning until the All-Channel Receiver Act took effect in 1964).

The school board's decision set WHYY-TV back nearly a year; after an agreement was reached to reorganize the board of directors and for the chairman and president of WHYY to present their resignations, the last obstacle was removed in February, with the station finally debuting on September 16, 1957. Six months after start-up, the first nighttime programs were presented by the station to complement daytime instructional output.

WHYY-TV had been on the air in Philadelphia for a year when events further down the Delaware River transpired that would have a major effect on the young station. Channel 12 in Wilmington had been occupied by WVUE, a commercial station. WVUE closed in September 1958, a casualty of ownership complications and financial losses, and within a week of its shutdown, committees involving Pennsylvania, Delaware, and New Jersey legislators were formed to study the feasibility of procuring channel 12 for regional educational broadcasting use while maintaining channel 35.

WHYY was not the only entity interested in channel 12. Other applicants also filed for authority to build it as a commercial station. As Delaware groups marshaled a demonstration in Washington in support of designating the VHF channel for educational use, the FCC convened hearings with WHYY and four commercial applicants to start in October 1960, then delayed into 1961.