Thomas Suozzi, who formerly held the seat, defeated Republican Mazi Pilip, the Associated Press projected.
Some cable news networks covered the special election as a bellwether for the November election.
The district covers Queens and Nassau counties.
Democrat Tom Suozzi entering a UPS facility on Tuesday.Tim Balk/New York Daily News/Tribune News Service via Getty Images
CNN dispatched correspondents to local precincts and carried live the results of the counting from individual ballot machines.
Santos was expelled from the House in December after a devastating House Ethics Committee report on his campaign finances.
He already had gained fame for his wild embellishments and lies about his resume and experience.
He added, The answer is to bring people of good will together to find that common ground.
With Suozzis election, Republicans will hold 219 seats and Democrats will have 213.
