Zach Bogosian (born July 15, 1990) is an American professional ice hockey defenseman for the Atlanta Thrashers of the National Hockey League (NHL). The first person of Armenian descent to play in the NHL, Bogosian attended Cushing Academy in Massachusetts before he joined the Peterborough Petes of the Ontario Hockey League (OHL) in 2006. He played two seasons in the OHL, and was nominated for the Red Tilson Trophy as the league's most outstanding player in his second season. Bogosian was regarded as a complete, physical defenceman who could contribute on both offense and defense; he was rated as one of the top players heading into the 2008 NHL Entry Draft, where the Atlanta Thrashers selected him third overall. He signed a contract with the team a few weeks after the draft and began the season with the Thrashers, though he missed several weeks of his rookie year due to injury. In his second season, he tied a team record for goals by a defenseman. Bogosian first played in an international tournament when he joined the American national team at the 2009 IIHF World Championship.
In 2004, Bogosian entered high school at Cushing Academy, a prep school in Massachusetts. The assistant coach of the school's hockey team was Ray Bourque, a former NHL defenseman who was elected to the Hockey Hall of Fame. Bogosian's teammates at Cushing included his older brother, Aaron, and Bourque's son, Ryan. While at Cushing he was used mostly as a fifth or sixth defenceman and played few minutes as a result. After his second year at the school, Bogosian was selected 19th overall in the 2006 Ontario Hockey League (OHL) Priority Draft by the Peterborough Petes Bogosian's decision to play in the OHL rather than go to the NCAA differed from most of his teammates, including his brother. As his father and uncle had also played college football in the NCAA, it was expected that Bogosian would follow them in going to university. He cited watching Ottawa 67's games at age nine as a major influence in deciding to play in Canada.
Bogosian began playing for the Petes in the 2006–07 season. He played 67 games for the team and finished with 7 goals and 26 assists for 33 points, which was second on the team in points for both rookies and defensemen. In recognition of his season, he was named to the OHL's Second All-Rookie Team, as one of the top four rookie defencemen in the league. The next season, Bogosian appeared in 60 games for the Petes. He led his team in scoring with 61 points (11 goals, 50 assists), the only defenceman in the league do so; the 50 assists he scored were second in the league among defensemen. The Petes reached the playoffs after missing the previous year, and Bogosian added another three assists in five games. During the season, he participated in both the OHL All-Star Classic and the CHL Top Prospects Game, an all-star game of prospects from the three leagues in the Canadian Hockey League (Western Hockey League, Quebec Major Junior Hockey League and OHL). At the conclusion of the season, Bogosian was named one of the five draft-eligible finalists for the Red Tilson Trophy as most outstanding player in the OHL, and was also named to the OHL First All-Star Team as one of the two best defensemen in the league.