The District added more than 2,200 residents to its voter rolls in June, city records show.
The D.C. Board of Elections said in a filing that it had 468,233 voters on its books through the end of June, an increase of 2,262 from May.
Ward 6, which includes Capitol Hill, logged 420 new voters, giving it the largest increase of any of the District's eight wards. Ward 4, which covers the city's northern tip, reported the fewest new voters, adding only 230.
About two in three voters registered as Democrats, but 27 percent of new registrants opted for the "no party" option.
The next D.C. election is scheduled for Nov. 6 and will include voting for president, D.C. Council chairman and two at-large council seats.