Amateur Born in
Ann Arbor, Michigan, and raised in
Farmington Hills, Michigan, Petry spent three years playing varsity hockey at
St. Mary's Preparatory, in nearby
Orchard Lake Village. He left prior to his senior season in November 2005 to play for the
Des Moines Buccaneers of the
United States Hockey League (USHL), a member of the team's 2006 Tier 1 National Championship-winning team. Petry was then drafted by the
Edmonton Oilers of the NHL in the second round of the
2006 NHL entry draft, 45th overall. He was the Oilers' highest draft pick that year, as the Oilers had previously traded their first-round pick to the
Minnesota Wild in exchange for
goaltender Dwayne Roloson. Petry would play the following season with the Buccaneers, once again helping the team reach the playoffs. In 2007, Petry accepted a scholarship with
Michigan State University. He registered 24 points (three goals and 21 assists) and was named to the
Central Collegiate Hockey Association (CCHA) All-Rookie Team in his freshman year. The following season for Petry saw a drop in performance, as he was held to a total of 14 points (two goals and 12 assists). He achieved a significant improvement to his game for his junior year at Michigan State, however, as he finished third overall in team scoring and first as a defenseman, collecting 29 points (four goals and 25 assists). Petry was ever-present for his team, playing in all the Spartans' games for the three seasons he was there.
Professional Edmonton Oilers (2010–2015) in February 2014. Upon completing what would be his final year at collegiate level, Petry signed a two-year, entry-level contract with the Edmonton Oilers on March 10, 2010. He was then briefly assigned to the Oilers' then-
American Hockey League (AHL) affiliate, the
Springfield Falcons, playing in eight games. He played his first game as a professional on March 26. On September 30, 2010, Petry was assigned by the Oilers to their new AHL affiliate, the
Oklahoma City Barons, for its inaugural season. On December 27, Edmonton recalled Petry from Oklahoma City. He then made his NHL debut against the
Buffalo Sabres on December 28, 2010, and recorded his first NHL point, a secondary assist on a goal by
Ryan Jones. His first NHL goal was scored on January 20, 2011, against
Kari Lehtonen of the
Dallas Stars. On February 4, 2011, Petry was reassigned back to the Barons. Petry improved in his second NHL season, leading all Oilers defensemen in points, with 25, and was trusted into a shutdown role alongside
Ladislav Šmíd. At the end of the
2011–12 season, on June 7, 2012, Petry re-signed on a two-year, $3.4 million contract with the Oilers. At the start of the
2011–12 season, Petry made Edmonton's NHL roster out of training camp and subsequently played three regular season games before being assigned to Oklahoma City. After only two games in the AHL, however, Petry was recalled back to Edmonton, where he remained for the entire season, playing in 73 games. After the Oilers missed the playoffs in
2012, Petry was invited to play for
Team USA at the
2012 IIHF World Championship. He amassed six points in nine games, though the United States were eliminated in the quarter-finals by
Finland. Petry stayed as a permanent member of the Oilers for the
lockout-shortened
2012–13 season, playing in all 48 games as the Oilers again failed to make the
Stanley Cup playoffs that year.
Montreal Canadiens (2015–2022) in April 2015. On March 2, 2015, during the
2014–15 season, Petry was traded to the
Montreal Canadiens in exchange for a
2015 second-round draft pick and conditional fifth-round pick. After the Canadiens post-season run, on June 2, 2015, Petry opted to surrender his impending free agent status in signing a six-year contract extension with the Montreal Canadiens until the 2020–21 season. On September 25, 2020, Petry signed a four-year, $25 million contract extension with the Canadiens. The
2020–21 COVID-shortened season proved to be Petry's most productive to date, while playing alongside Montreal newcomer
Joel Edmundson. His 42 points over 55 games was second on the team, behind only
Tyler Toffoli. Petry participated in the Canadiens' deep run during the
2021 Stanley Cup playoffs, culminating in an appearance in the
2021 Stanley Cup Finals, where they lost to the
Tampa Bay Lightning in five games. Petry sustained a finger injury in the course of Game 3 of the second round series against the
Winnipeg Jets, causing him to miss two games. He opted against surgery to remain in the series, instead having it put in a cast, the pain from which caused blood vessels in both his eyes to pop, and he returned to Game 2 of the semi-final against the
Vegas Golden Knights with noticeably bloodshot eyes that became an
internet meme. With
Shea Weber's departure from the lineup for health reasons, Petry became the Canadiens' top defenseman going into the
2021–22 season. In December, shortly after the sacking of longtime general manager
Marc Bergevin, the team announced that Petry was dealing with an upper body injury and would miss an undetermined number of upcoming games. The change in management with the hiring of
Jeff Gorton and possibility of the Canadiens initiating a long-term rebuild raised questions about whether Petry would seek a trade. He said "when you get later in your career — as a I am — you know time's not on your side. So that's a decision that they need to make and to be aware of what they're going to do." Petry was vocally critical of coach
Dominique Ducharme. His situation became more complicated still when his wife Julie became frustrated with
the Quebec government's pandemic measures and relocated with their children to
Detroit for the remainder of the season. Following Ducharme's sacking by new general manager
Kent Hughes and the hiring of
Martin St. Louis to replace him, Petry's play markedly improved. After returning, he played what was widely judged as his best hockey of the season in the final weeks of April, including a two-goal performance to help the team beat the
New York Rangers 4–3, snapping a nine-game losing streak in the penultimate game of the year. Having been acquired by general manager
Ron Hextall in the hopes that he would improve the offensive performance of the Penguins' blueline, there was a general sense of disappointment with Petry's first season with the team, despite generating 31 points in 61 games. He missed time with injury, and in the midst of an underwhelming season for the Penguins that saw them miss the playoffs for the first time in 17 years, there were reports that new general manager
Kyle Dubas was looking to trade Petry elsewhere.
Detroit Red Wings (2023–2025) On August 6, 2023, Petry, alongside
Casey DeSmith, Nathan Legare, and a 2025 second-round pick, was traded back to Montreal in exchange for
Rem Pitlick and
Mike Hoffman as part of a three-team trade also involving the
San Jose Sharks. It was widely speculated that general manager Hughes would seek to immediately trade Petry to another team; as a result, Petry was again traded to the
Detroit Red Wings in exchange for
Gustav Lindström and a conditional 2025 fourth-round pick on August 15. During the
2024–25 season, he recorded one goal and seven assists in 44 games for the Red Wings.
Florida Panthers (2025–2026) On July 1, 2025, Petry signed as a free agent to a one-year, $775,000 contract with the
Florida Panthers for the season. On November 17, 2025, Petry played his
1,000th NHL game, becoming the 413th player to reach the mark.
Minnesota Wild (2026–present) As a pending free agent, Petry was traded to the
Minnesota Wild on March 5, 2026, in exchange for a conditional
2026 seventh-round pick. ==Personal life==