The Giants did not announce terms of the deal, but Thomas' agent told ESPN's Adam Schefter that the 2020 first-round draft pick agreed to a five-year, $117.5 million extension that includes $67 million guaranteed at signing, a record for an offensive lineman.
Thomas, 24, is now under contract with the Giants through the 2029 season. The $67 million fully guaranteed at signing is the most ever for a non-quarterback first-round extension after three years.
"Again, 24½-year-old left tackle that we now have locked up for seven years," Giants general manager Joe Schoen said Wednesday. "So, ecstatic about that as well."
The $67 million guaranteed puts Thomas ahead of Baltimore's Ronnie Stanley ($64.1 million), New Orleans' Ryan Ramczyk ($60.2 million), Houston's Laremy Tunsil ($60 million) and Kansas City's Jawaan Taylor ($60 million).
These are burdens that Thomas insists on embracing.
"It's a blessing -- something I work hard for and something I'm going to continue to work hard for to live up to that," Thomas said. "It's a blessing to my family -- to my kids that I don't even have yet. I'm excited for it and excited to be here for a while."
The 6-foot-5, 315-pound Thomas emerged as one of the NFL's best left tackles last season, earning second-team All-Pro honors while anchoring an offensive line that helped the Giants finish with the league's fourth-best rushing offense.
Thomas is the third player drafted by New York's previous front-office regime to sign a long-term deal this offseason. Schoen, in his second year, signed quarterback Daniel Jones to a four-year, $160 million deal in March and signed defensive tackle Dexter Lawrence to a four-year, $90 million extension in May.
The No. 4 overall selection in 2020, Thomas has appeared in 45 games, including 44 starts, over the past three seasons with the Giants. The former University of Georgia star struggled early in his career but has turned it around, finishing 10th last season among offensive tackles with a 92.6% pass block win rate.
New York picked up the fifth-year option on Thomas' rookie deal earlier this year and had him under contractual control for at least the next two seasons, before even factoring in potential franchise tags.
But Thomas and the Giants elected to get something done after three seasons. Thomas had no problem getting a deal done now rather than waiting out a market that is likely to explode.
"I would say security -- that's the biggest thing," Thomas said. "Guarantees and things like that, especially with my history of ankle injuries and things of that nature.
"Playing offensive line, people falling on you every game -- you want to be secure. You don't hope for injuries but you know that's a thing that happens in this league."