He was drafted by the Buffalo Sabres 83rd overall in the fourth round in the 1992 NHL Entry Draft. Barnaby was drafted from the QMJHL where he spent four seasons with the Beauport Harfangs, Verdun Collège Français and Victoriaville Tigres, leading the league in penalty minutes in consecutive seasons in '92 and '93. After completing his QMJHL career with the Tigres, Barnaby joined the Sabres for the end of 1992–93 season. Barnaby was generally considered a pest and agitator and spent the next few seasons playing between the Sabres and AHL affiliate the Rochester Americans. Barnaby established a full-time role with the Sabres in the 1995-96 recording a career-high in penalty minutes with 335. He was frequently involved in on-ice altercations and among other incidents he made headlines in 1996, when in a game against the Philadelphia Flyers after a few hits and Barnaby lying on the ice presumably injured, a brawl between the two teams started. With the brawl in full motion, Barnaby jumped to his skates to punish Garth Snow, goaltender of the Flyers, who was poking Barnaby with his stick while the officials weren't looking. In 1996-97 Barnaby showed his scoring talents when he scored a career-high 19 goals and 43 points in 68 games. After seven seasons with the Sabres organization during the 1998–99 season, Barnaby was traded by the Sabres to the Pittsburgh Penguins in exchange for Stu Barnes on March 11, 1999. One of his most celebrated fights came the following season in 2000 against his former Sabre teammate Rob Ray after dining with Ray the previous night. Barnaby played in 129 games with the Penguins before he was traded on February 1, 2001, by Pittsburgh to the Tampa Bay Lightning in exchange for Wayne Primeau. After struggling to provide an impact to start the 2001–02 season for the Lightning, Barnaby was again traded to the New York Rangers for Zdeno Ciger on December 12, 2001. After going scoreless with the Tampa Bay in 29 games Barnaby responded with resurgence of form with the Rangers, scoring 21 points in only 48 games. Matthew became a fan favourite in the Big Apple and played in 196 games before he was traded to the playoff bound Colorado Avalanche in the 2003–04 season, for David Liffiton and Chris McAllister on March 8, 2004. On July 2, 2004, he signed a lucrative three-year contract with the Chicago Blackhawks. After the 2004 NHL Lockout, Barnaby played his first season with the Hawks in 2005–06. Suffering from the year of hiatus he was subsequently bought-out of his contract following the season. Barnaby, again a free agent, signed a one-year deal with the Dallas Stars on July 5, 2006. In the 2006–07 season, Barnaby recorded his 300th, and final point, on December 23, 2006 against the Edmonton Oilers. He played only 39 games with the Stars before suffering a season ending concussion against the Phoenix Coyotes on January 9, 2007. Struggling with the effects of his concussion Barnaby announced his retirement from the NHL in July 2007.
Broadcasting career
In September 2007, it was announced via the Sabres website that Barnaby would be given a tryout for replacing Jim Lorentz as color commentator for the Sabres. He served in that capacity for the September 26th pre-season game. The permanent position, however, went to Harry Neale instead. He also co-hosted The Enforcers on Time Warner Cable SportsNet with Rob Ray until joining ESPN as an NHL analyst in late 2008. Barnaby was forced to depart Time Warner Cable SportsNet after joining ESPN as its lead NHL analyst in October 2008, when Barry Melrose returned to the league to coach the Tampa Bay Lightning. Melrose returned to the network shortly after being fired just 16 games into the season. He is an occasional broadcaster and analyst for the showNHL on TSN and will serve as an analyst for their new hockey highlights show That's Hockey 2Nite. On December 5, 2011, ESPN terminated its contract with Barnaby after his arrest on suspicion of DWI earlier in the day.
Personal
Barnaby is known for his affable character off-ice and is one of the league's most willing interviewees. While with the Penguins, Barnaby was known for his charity work, being very fan friendly, and had a very loyal band of fans named the "Barnaby Brigade". He had a long-standing feud with Lyle Odelein, Barnaby infamously referred to his longtime rival as "Cornelius," a reference to the Roddy McDowall character in Planet of the Apes. He is mostly of Anglo-Canadian origins, but speaks fluent French, having moved to the province of Quebec with his family, at a young age. He is very attached to the Québécois community and is a big Montreal Canadiens fan. Barnaby was recently arrested a third time in Nashville, TN while visiting his son with girlfriend Rhonda White, whom was previously married to Paul Rushforth. He is said to have choked a bouncer and was also arrested for public intoxication.
Post-hockey
Barnaby lives in Ottawa. In 2019 he started a podcast called "Unfiltered with Matthew Barnaby" Matthew is a hockey analyst on The Power Play on SiriusXM channel 91. Matthew has also partnered up with a dynamic group of entrepreneurs to bring groceries to your local Home Hardware. The company is called Hunger Cave. Matthew is also heavily involved in charitable work raising money for Alzheimer’s. He has personally been involved in endless events and has helped raise millions of dollars for a disease that touches close to his heart.