Florida Gov. Ron DeSantis, long seen as Donald Trump's leading rival for the Republican nomination, plans to launch his 2024 presidential campaign on Wednesday in an online conversation with Twitter CEO Elon Musk, according to two people with knowledge of the decision.

DeSantis, an outspoken cultural conservative, will outline his plans in an evening audio event streamed on Twitter Spaces, according to the two people. They spoke to The Associated Press on condition of anonymity because they weren't authorized to discuss the announcement publicly.

The 44-year-old two-term governor joins a crowd...