Rep. A. Donald McEachin, D-Va., died on Monday at the age of 61.
His chief of staff said in a statement that the congressman had been battling the "secondary effects" of colorectal cancer since 2013.
"We are all devastated at the passing of our boss and friend," Tara Roundtree said.
McEachin was first elected to Congress in 2016. He won reelection last month.
House Speaker Nancy Pelosi paid tribute to McEachin, saying the Democrat was "a tireless champion for Virginia families and a force for economic opportunity and environmental justice."
McEachin's office said it would continue serving the people of Virginia's 4th Congressional District until a new representative is elected.
McEachin is survived by his wife and three children.