The contract, which starts in 2023-24, will keep the 23-year-old center with the Blues through the 2030-31 season. He could have become a restricted free agent at the end of next season, the last of the two-year, $5.6 million contract ($2.8 million AAV) he signed on Sept. 21, 2021.
"Yeah, I think it's pretty cool," Thomas said. "I think being able to be in St. Louis for eight more years is so exciting."
Thomas had NHL career highs last season in goals (20), assists (57) and points (77) in 72 games. His 57 assists were the most by a St. Louis player since Pavol Demitra also had 57 in 2002-03.
Thomas had six points (two goals, four assists) in 12 games in the Stanley Cup Playoff, when the Blues were eliminated in six games by the Colorado Avalanche in the Western Conference Second Round.
"We look at him as the centerpiece of our organization moving forward," St. Louis general manager Doug Armstrong said. "It reminds me actually of signing (defenseman Alex) Pietrangelo and (forward Vladimir) Tarasenko, both coming off their age 22 [season], we signed them to long-term deals. We felt they were cornerstone players. We feel that's Robert."