The ad, paid for by the group United We Win, begins by showing images of Buttigieg with the narration “He’s a Rhodes Scholar, a successful mayor, a uniter.”
“No, not that guy,” the ad continues. “It’s Cory Booker.”
It then touted accomplishments by Booker while serving a mayor of Newark, N.J., and later as a senator.
“This Rhodes Scholar mayor has what it takes to beat Donald Trump,” the narrator concluded.
CNN reported Friday that the advertisement will begin airing on Tuesday in Des Moines and Cedar Rapids.
Booker told the news network in an interview that he was unaware of the ad until he was shown a clip of it.
When asked whether he was running against “that guy,” Booker said: “I’m running for the soul of our country.”
“We need to be a Democratic party that can unify and come together, so I celebrate the people that are in the race and my campaign is not about tearing anybody down,” he added.
Booker has previously disavowed super PAC funding, as the groups do not have to legally disclose their donors publicly. Another pro-Booker super PAC, Dream United, shut down Wednesday after struggling to raise money and falling drastically short of its $10 million goal.
Buttigieg’s campaign has seen momentum in Iowa in recent weeks. Polling aggregation website Real Clear Politics has him in first place in the state.
Both men are among more than a dozen candidates vying for the 2020 Democratic presidential nomination.