The series was promoted as part of Expanding the Universe, a Marvel Studios special that debuted on Disney+ on November 12, 2019.[19] In December, Feige debuted the first image from the series at Comic Con Experience. Vinnie Mancuso of Collider found the image to be "very interesting", highlighting the "old-school black and white" coloring.[41] A commercial for the series, The Falcon and the Winter Soldier, and Loki was shown during Super Bowl LIV.[42] Inverse's Dais Johnston noted that the clips shown visually referenced past sitcoms spanning different eras, including The Dick Van Dyke Show (1961–1966), Leave It to Beaver (1957–1963), Bewitched (1964–1972), The Brady Bunch (1969–1974), Roseanne (1988–1997), and Full House (1987–1995). Johnston thought the series would be "a must-see not only for Marvel fans but also for anyone looking for a hit of nostalgia: the era-spanning framework means anyone can relive the shows of their childhood in this age of streaming."[43] Julia Alexander of The Verge said the footage "wasn't much" but offered "enough glimpses to tease fans".[44] Haleigh Foutch at Collider felt of all the Super Bowl commercials, Marvel's teasers "stole the whole show" and had "a lot to get excited about". Foutch said the WandaVision footage was "the most exciting", saying it was "utterly strange and unpredictable looking".[45]

The series' official trailer was released on September 20, 2020, during the 72nd Primetime Emmy Awards.[46] The trailer received 55.7 million views online within 24 hours, including 36.1 million on YouTube, 4.9 million on Facebook, and 10.1 million on Instagram, which was believed to be the highest number ever for a trailer for a series on a streaming service. The views were also compared to those that trailers released during the Super Bowl receive. WandaVision also had over 302,600 social mentions, trending on Twitter immediately after the short teaser aired during the Emmy Awards ahead of the full trailer's release, ultimately trending fourth on the service; the trailer was the number two trending video on YouTube as well.[47] [B]Ethan Anderton from /Film noted the footage in the trailer "looks like one of the most trippy Marvel projects to date". He also pointed out Vision wearing a Halloween costume version of the character's comic design as an indication there would be "more lighthearted stuff in this series too".[48] Matt Patches at Polygon called the trailer "a hoot, full of bright colors and odd behavior", adding that it still left much of the series a mystery.[27] Comic Book Resources' Noah Dominguez said the trailer "offers quite a bit in terms of content" with "a vivid look at some of the visual tricks on display".[49] Charles Pulliam-Moore of io9 called the trailer's use of "Twilight Time" by The Platters "the most haunting" of "all the strange things featured in" it. As well, he felt the trailer was edited to create "the effect of rapidly flipping through television channels in search of something good to watch", and pointed out how the static visuals when Wanda changed things around her made "it unclear whether what she's interacting with is real or not". [/B]Moore also said the last part of the trailer showing Teyonah Parris as the adult Monica Rambeau was the trailer's "money shot".[10] The Hollywood Reporter's Richard Newby called the trailer "jam-packed with information, and gives fans quite a lot to look forward to, as well as some mysteries to ponder over leading up to the premiere".[28]