The worlds of entertainment and social media came together unexpectedly Monday as Kevin Mayer, the head of Disney Plus, said he was leaving the company to take the chief executive role at Chinese-owned viral-video titan TikTok.

The move gives a shiny Hollywood face to a company that has come under harsh criticism from lawmakers over its Beijing influence and also raises questions about succession at Disney Plus, a core part of that firm’s strategy.

TikTok parent ByteDance said Mayer will also become chief operating officer of that company, a growing juggernaut with some 60,000 employees around the world, in a newly created role.

Mayer’s “wealth of experience building successful global businesses makes him an outstanding fit for our mission of inspiring creativity for users globally,” ByteDance chief executive Yiming Zhang said in a news release.

In addition to TikTok, which has become massively popular with teenagers, ByteDance owns the trending-video platform TopBuzz, the photo app FaceU and the social app Helo, among other properties. Mayer will start June 1 and will be based in Southern California.

Alex Zhu, TikTok’s former leader, will become a vice president of product and strategy at ByteDance.

In response to Mayer’s exit, Disney said it would promote company veteran Rebecca Campbell, currently president of Disneyland Resort, to take his place. Campbell had previously been an executive at the streaming division, focusing on the Disney Plus launch in Europe, Africa and the Middle East.

Mayer leaves Disney after he failed to be named to the chief executive spot following the departure of Robert Iger in February. Bob Chapek, who runs the theme-park division, was named to the role, prompting speculation at the time over whether Mayer would seek to leave the conglomerate.

Mayer said in a statement that he was “excited to help lead the next phase of ByteDance’s journey as the company continues to expand its breadth of products across every region of the world.”

The executive was credited with helping to develop and launch Disney Plus, which has been a consumer if not yet profit success story with 54 million paid subscribers as of earlier this month, according to Disney.

But his skills are a more unexpected fit with TikTok, which is far from the high-gloss professional content of Disney Plus, instead focused on a heavy volume of homemade videos. Analysts say one question to watch will be whether Mayer will push the site in a more high-end direction.

Yiming, the ByteDance chief executive, said he thought Mayer could “take ByteDance’s portfolio of products to the next level.”

More immediately, Mayer could also have his work cut out on the political front. TikTok faces bipartisan questions on Capitol Hill over privacy and surveillance concerns. In the fall, Senate Minority Leader Charles E. Schumer (D-N.Y.) and Sen. Tom Cotton (R-Ark.), asked Joseph Maguire, then the acting director of national intelligence, to look into the company’s data-collection tactics as well as censorship by the Chinese government.

“With over 110 million downloads in the U.S. alone, TikTok is a potential counterintelligence threat we cannot ignore,” the lawmakers wrote. It remains to be seen whether the addition of an American executive would placate those concerns. His appointment was immediately highlighted on Twitter by Sen. Josh Hawley (R-Mo.), who noted his frustration with TikTok’s refusal to send high-level executives to Washington to testify before Congress.

“[TikTok] previously told me they couldn’t attend hearings and testify because executives were located in #China,” Hawley tweeted. “But this new executive lives in the USA. I look forward to hearing from him. Under oath.”

The executive would not be made available for comment, said a TikTok spokesman. A Disney spokesman did not respond to a request for comment.

Zhu last year had sought to meet with leaders to allay their worries, though the company’s executives declined to appear at a congressional hearing in March to answer questions about their practices. Relations between lawmakers and TikTok have been challenged as part of the larger economic and more recent virus-related tensions between China and the United States.

ByteDance has continued to gain in influence. The company not long ago hit 1 billion active users, many under age 25. TikTok is often the most downloaded app on the Apple store.

The pandemic has cemented the app’s popularity further, as users have uploaded videos of themselves in quarantine; many have then gone viral or made their way to late-night talk shows.

Meanwhile, Disney Plus will try to move ahead without Mayer as it looks to the service to provide revenue while many other realms, from theatrical films to ESPN, are severely curtailed because of the coronavirus.

Campbell said in a statement that “armed with the best creative content engines and technology teams in the industry, I am extremely confident in our ability to continue growing the [Disney Plus] business around the globe.”

The Mayer news represents the latest close relationship between Disney executives and the Chinese government. Companies owned by the Shanghai government are the majority investor in Shanghai Disneyland, and Marvel and other Disney movies regularly get the country’s coveted theatrical distribution slots.