The 27-year-old has agreed a contract worth $38.75m (£25.75m) with the NFC East side.
Beatty told the team's website: "It's good to be home. It's a great feeling. You could be going through free agency, but when that happens a lot of stuff is going through your mind. That feeling is no longer there.
"You're settled in with a great team, a team I love playing for. I know the coaching staff. I'm looking forward to getting back in it and moving forward."
General manager Jerry Reese added: "We are very pleased to get a new deal done with Will. We believe he is one of the ascending left tackles in the NFL."
Beatty has played for the Giants since 2009.