The Massachusetts senator defeated his Republican challenger Kevin O'Connor, who he faced after a grueling Democratic primary battle with Rep. Joe Kennedy (D-Mass.) earlier this year.
Ed Markey wins 2020 Massachusetts Senate race
The senator's re-election also ensures that one of the most vocal supporters of net neutrality remains in Congress's upper chamber.
Markey has pushed the Save the Internet Act, a bill that would essentially make the 2015 Open Internet Order, the Federal Communications Commission (FCC) rule that established net neutrality before being repealed, a law.
The Save the Internet Act passed in the House of Representatives in April last year, but has since languished in the Senate.
Depending on how the rest of the election shakes out, net neutrality could once again become a major tech policy issue.
The win for Markey is not overly shocking. As FiveThirtyEight shows, recent polls for Markey found him leading O'Conner by double digits in early October and mid-October.