As an English-language independent station

The station first signed on the air on January 1, 1970, as WSMW-TV, an independent station based in Worcester that featured English-language general entertainment programs including old movies (including the entire series of Abbott and Costello movies and the Bowery Boys/Dead-End Kids movies starring Huntz Hall), cartoons, religious shows (including the Jacob Brothers and The PTL Club), a cooking show (Cooking with Bernard), science fiction shows (such as UFO), dramas (including Maverick and Thriller), as well as sitcoms (including The Phil Silvers Show and Petticoat Junction). Though WSMW-TV was within the Boston market, it was far enough from Boston itself that the station was able to air some of the same shows as the Boston stations, in a similar situation to WMUR-TV (channel 9), the ABC affiliate in Manchester, New Hampshire. The station's call letters stood for State Mutual (Insurance Co.) in Worcester, the corporate owner of the station.

WSMW's original logo from 1970 to 1982.

WSMW also broadcast sports programs; from its debut through the end of the 1971–72 NBA season, the station was the television home of the Boston Celtics. In 1970 and 1971, WSMW broadcast (same-weekend tape-delayed coverage of) New England Patriots preseason games. WSMW also offered extensive coverage of college basketball throughout the 1970s, mostly games of the College of the Holy Cross and Assumption College, with some Boston College, University of Massachusetts Amherst, and Bentley College games included on the schedule. The broadcast team of play-by-play man Bob Fouracre and analyst Bob Cousy worked these games. During the college football season, the station carried a taped two-hour broadcast of a game from earlier in the day on Saturday nights at 10:30 p.m. These games were typically Holy Cross home games, and when Holy Cross was on the road, games from UMass. Fouracre worked these games, and the analyst most of the time was Gino Cappelletti. WSMW also broadcast Bay State Bowling, a weekly candlepin bowling program on Sunday evenings for most of the 1970s, which was hosted by Fouracre.

In 1970, shortly after the cancellation of the long-running Bozo's Circus on WHDH-TV, WSMW-TV debuted their own version of the Bozo the Clown series franchise, Bozo's Big Top. Tom Matzell played Bozo, alongside Gene Sanocki as Bozo's sidekick Professor Tweetyfoofer. Local children were featured on the program daily, with many waiting up to one year or more for their chance to be on the show. This version aired until 1974.

In the fall of 1980, channel 27 began running the subscription television service Preview at night after 7 p.m. In February 1983, the station expanded Preview to begin weekday programming at 5 p.m. and 2 p.m. weekends. Then on July 1, 1983, the station dropped all of its entertainment programs and began running Preview 21 hours a day, with the remaining hours from 6 to 9 a.m. devoted to religious and public affairs programming. In the spring of 1985, WSMW cut Preview's broadcast hours down to 7 p.m. to 3 a.m. on weekdays and after 3 p.m. on weekends; it also brought back some general entertainment programs. Hill Broadcasting bought the station in late 1985, and changed the station's call letters to WHLL. At that time, WHLL dropped Preview and reverted to being a general-entertainment independent full-time.

WUNI's former Univision 27 logo. Variations of this logo were used from the mid-1990s through 2012.

Initially, WHLL's schedule consisted of B-grade movies, drama series, public domain cartoons and a few sitcoms, as well as religious programs. While the station again initially shared some of its programming with Boston stations, by the fall of 1986 the duplication had largely been eliminated, and WHLL began to market itself as a Boston station. When cartoons and sitcoms were gone around 1987, the station began running preempted network programming from NBC, ABC, and CBS (that were declined by WBZ-TV channel 4; WCVB-TV channel 5; and WNEV-TV channel 7, now WHDH), which had previously aired on Boston's WQTV (channel 68, now WBPX-TV) and started airing shows from the BBC and Australia's Nine Network as well as new cartoons. WHLL also began running some first-run syndicated shows by 1988, as well as a good amount of religious programming. During the station's tenure as WHLL, it employed WMJX radio personality David Allan Boucher as its booth announcer.

Addition of Spanish programming and Univision affiliation

In 1992, the station added Spanish programming as a part-time affiliate of Telemundo, with the network's programming running from 4 or 5 p.m. until about 1 a.m. By 1993, when the Jasas Corporation acquired the Hill Broadcasting stations, WHLL ran Spanish-language programs after noon; much of the remaining English-language programming consisted of preempted network shows and religious programs. That year, the station became an Univision affiliate and changed its call letters to WUNI. In 1995, the station began carrying Spanish language programming full-time. The station was purchased by Entravision Communications in 2000.

On February 18, 2011, Rhode Island cable provider Full Channel TV, Inc. (now known as i3 Broadband) dropped WUNI from its systems and replaced the station with Univision's national feed on its digital cable tier; the impetus for the removal was a breakdown in negotiations over claims that Entravision demanded "a 33% increase in retransmission fees" as a cash payment to renew its carriage deal with WUNI.^[2]

2017 call sign and channel swap

On December 4, 2017, as part of a multi-market realignment, the programming and call signs of WUNI and sister station WUTF were swapped: WUNI and its Univision programming moved to the Univision-owned facility using digital channel 27 and virtual channel 66, while Entravision's digital channel 29 and virtual channel 27 facility became the new home of UniMás affiliate WUTF.^[3]

Notable former on-air staff

• Upton Bell – college football color commentator (1978–1982)
• Doug Brown – sports anchor (1982–1983)
• Gino Cappelletti – college football color commentator
• Bob Cousy – college basketball color commentator
• Cy Follmer – sports anchor, Boston Celtics play-by-play announcer, New England Patriots play-by-play announcer (1970–1971)
• Bob Fouracre – sports anchor, Bay State Bowling host, Boston Celtics play-by-play announcer, college football and basketball play-by-play announcer (1971–1982)
• Stephen Guptill – elderly affairs reporter, host of The Elder American (1971–1975)
• Togo Palazzi – college basketball color commentator
• Doug White – news anchor (1970–1972)

Subchannels

The station's signal is multiplexed:

Analog-to-digital conversion

WUTF (as WUNI) shut down its analog signal, over UHF channel 27, on June 12, 2009, the official date on which full-power television stations in the United States transitioned from analog to digital broadcasts under federal mandate. The station's digital signal continued to broadcast on its pre-transition UHF channel 29,^[5] using virtual channel 27.