WASHINGTON — A US military member is expected to face criminal charges after winning more than $1 million betting on Polymarket ahead of looming American actions against Iran and Venezuela.

The staggering and brazen windfall, first reported by the Wall Street Journal, was confirmed to The Post by a source familiar with the investigation.

The identity of the newly minted millionaire remains unclear, as do the particular operations on which the service member gambled.

It’s likely to be the latest high-profile bust by the Justice Department, which in April charged an Army special forces member with earning $400,000 betting on the US capture of Venezuelan President Nicolás Maduro.

In that case, prosecutors are alleging unlawful use of confidential government information for personal gain, wire fraud and money laundering.

In July, President Trump’s longtime teleprompter operator was placed on leave after being caught winning $100,000 with bets on Kalshi about the content of speeches ahead of their delivery.