Kevin McCarthy said the inquiry would focus on "allegations of abuse of power, obstruction and corruption" by Mr Biden.
"I am directing our House committee to open a formal impeachment inquiry," McCarthy said, saying the Democratic president lied to the American people about his son Hunter's foreign business dealings.
"House Republicans have uncovered serious and credible allegations about President Biden's conduct," he said. "Taken together, these allegations paint a picture of a culture of corruption."
The White House immediately condemned the move, calling it "extreme politics at its worst."
"House Republicans have been investigating the President for 9 months, and they've turned up no evidence of wrongdoing," Ian Sams, White House spokesman for oversight and investigations, said on X, formerly known as Twitter.
So Why Now
According to the BBC, Republicans have been investigating the president since they took control of the House in January. The hearings have found no concrete evidence of misconduct by Mr Biden.
The Democrats, for their part, say any impeachment inquiry allows Trump to turn the House of Representatives into an arm of his 2024 presidential election.
An impeachment inquiry, meantime, would distract attention from the massive legal troubles weighing on Trump, who faces 91 criminal charges that will play out in four trials over the coming year.
"McCarthy is doing this for a very simple reason: If he doesn't, he'll be replaced as Speaker," political scientist Larry Sabato told AFP.