Carl Icahn is already profiting from Donald Trump’s victory.

The billionaire activist who campaigned for the Republican was at the Trump victory party Tuesday night when he excused himself — to invest $1 billion in the market, he told two media outlets.

He did so when the Dow futures were off 800 points — he felt certain the dip was overblown and that stocks would recover.

“I tried to put a lot more [than $1 billion] to work, but I couldn’t,” he said.

Icahn also profited when shares in his mid-size refiner, CVR Energy, rose 25 percent Wednesday, part of a broader rally in the energy patch.