Elon Musk has said he is committing around $45 million a month to a new pro-Trump super PAC

Elon Musk has said he plans to commit around $45 million a month to a new super political-action committee backing former President Donald Trump’s presidential run, according to people familiar with the matter.

Other backers of the group, called America PAC, include Palantir Technologies PLTR 2.14%increase; green up pointing triangle co-founder Joe Lonsdale, the Winklevoss twins, former U.S. ambassador to Canada Kelly Craft and her husband, Joe Craft, who is chief executive of coal producer Alliance Resource Partners ARLP -0.04%decrease; red down pointing triangle.

Formed in June, America PAC is focused on registering voters and persuading constituents to vote early and request mail-in ballots in swing states, according to one of the people. The coalition assessed that the Democrats have historically had very robust “get out the vote” campaigns and took note of the amounts of money that the Biden camp has dedicated to so-called on-the-ground efforts in swing states. America PAC will try to counter that.

Musk is currently the world’s richest person, with an estimated fortune exceeding $250 billion. The amount that he has said he plans to commit to America PAC is an extraordinary sum.

While it can be difficult to trace the full scope of some political giving, the largest known donation of the 2024 election so far is $50 million given recently by the great-grandson of banker Thomas Mellon to a super PAC supporting Trump.

America PAC has hired hundreds of employees for its efforts, and has been registering voters, having conversations with constituents in swing states and urging voters to request mail-in ballots, some of the people familiar with the matter said.

According to a filing made on Monday, America PAC had $8.75 million in contributions for the three-month period ending on June 30. Musk had indicated that he planned to start his donations in July, one of the people said.

In addition to Lonsdale, the Winklevosses and the Crafts, the filing listed a number of other donors to America PAC, including several with close connections to Musk.

Bloomberg News earlier said that Musk has donated to America PAC. The scale of his planned commitment hasn’t been reported.

Musk in March tweeted that he didn’t intend to donate to either Trump or President Biden’s campaigns. But the billionaire Tesla CEO has gotten closer to the former president in recent months.

On Saturday, Musk formally endorsed Trump for president after a shooter attempted to assassinate the former president at a Pennsylvania rally. “I fully endorse President Trump and hope for his rapid recovery,” Musk said on X. In a subsequent post he said, “Last time America had a candidate this tough was Theodore Roosevelt.”

The Wall Street Journal reported in May that Musk and Trump had been talking frequently in recent months and were developing a friendly rapport, and that Musk was helping organize a data-driven project to prevent voter fraud that Trump was briefed on. The article said the two men had also discussed a possible advisory role for Musk in a potential second Trump administration, something Musk later denied.

Jim Oberman contributed to this article.

Write to Dana Mattioli at dana.mattioli@wsj.com, Emily Glazer at Emily.Glazer@wsj.com and Khadeeja Safdar at khadeeja.safdar@wsj.com