"Jason is a veteran forward and a Stanley Cup Champion who will be a valuable addition to our club," Armstrong said in a team press release. "He's a proven leader and we are excited that he has decided to wear the Blue Note."
Regarding Langenbrunner, Armstrong added "We're excited to add a veteran forward with two Stanley Cup rings to our roster. Jamie is a solid player who will bring years of NHL experience on and off the ice for our hockey club."
Arnott, 36, has played in 17 NHL seasons, appearing in 1,172 games, compiling 904 points (400 goals, 504 assists) along with 1,216 penalty minutes.
Last season, the 6’5”, 220-pound forward played in 73 games between the New Jersey Devils and Washington Capitals, tallying 31 points (17 goals, 14 assists).
A member of the 2000 Stanley Cup Champion New Jersey Devils, Arnott has recorded 72 points (31 goals, 41 assists) in 115 NHL playoff games.
Langenbrunner, 35, has played 16 NHL seasons, appearing in 1,035 games and amassing 638 points (237 goals, 401 assists) along with 805 penalty minutes.
Last season, the 6’1”, 205-pound forward played in 70 games combined with the New Jersey Devils and Dallas Stars, recording 32 points (nine goals, 23 assists).
A two-time Stanley Cup Champion (Dallas 1999, New Jersey 2003), Langenbrunner has registered 86 points (33 goals, 53 assists) in 137 NHL playoff games.
Both players have also served as captains: Langenbrunner for four seasons in New Jersey (2007-11) and Arnott for three seasons in Nashville (2007-10).
"I had a few offers, but I heard nothing but great things about the organization from players that I've played with," Arnott told the St. Louis Post-Dispatch on Wednesday. "It seemed like a great fit for me...come in and be a guy to help out the young guys and contribute as much as a I can."
Added Head Coach Davis Payne, "To have two guys that understand what winning and success is in this league come in and play a role in that to provide an example, both daily and in game, is great for our team."
Information from Blues press releases was used for this report.