A deal would give the retail behemoth a key technology to reach younger shoppers and build out its third-party marketplace and advertising business.
Shares of both Microsoft and Walmart rose on the news.
“We are confident that a Walmart and Microsoft partnership would meet both the expectations of U.S. TikTok users while satisfying the concerns of U.S. government regulators,” Walmart said.
Microsoft did not immediately respond to FOX Business’ request for comment.
ByteDance, the Chinese company that owns TikTok, was ordered by President Trump earlier this month to sell its U.S. assets within 90 days or be barred from conducting business in the country. The Trump administration has long argued TikTok's data collection could pose a national security threat.
A deal could also include TikTok's Canadian, Australian and New Zealand businesses.
ByteDance has not yet announced a buyer but is expected to do so in the coming days. Bids from business-software provider Oracle and other companies are also being considered.
One Wall Street analyst, however, believes a combination of Walmart and Microsoft will be too difficult to beat.
"This is the final piece of the puzzle that ultimately cements Microsoft successfully acquiring TikTok's U.S. operations for likely $35 billion to $40 billion," wrote Wedbush analyst Dan Ives, who believes the business could be worth about $200 billion in a few years.
The joint bid comes hours after the resignation of TikTok CEO Kevin Mayer, who spent just three months on the job. Mayer blamed a charged political environment for his exit.