Moran, 68, said he would retire at the end of the year because "it's time for close this chapter of my life and move on to the next challenge," the Washington Post reported.
He is the ranking member of the House Appropriations Committee's interior subcommittee and a senior member of the defense subcommittee.
His strongly Democratic district, just across the Potomac River from the nation's capital, voted 68 percent for President Obama in 2012.
In a statement from the White House, Obama applauded Moran for pushing to "create jobs and economic opportunity for hardworking Virginians," and for having "consistently demonstrated a commitment to growing a strong American economy."
"And because of Jim's leadership, our brave service members and veterans are better protected, our civil service is stronger, and our air and water are cleaner and safer," the president said, adding he and first lady Michelle Obama thank him for his service, and "wish him and his family the very best in the future."