Marian Hossa spent only one season with the seniors of Trencin. In 1996-97, he was 17 and within a period of one year, he managed to suit up for three championships. At the start of the year he played in the World Junior Championship, then the European Championship and immediately after that, he traveled to the senior tournament in Finland. In the summer of 1997 the Ottawa Senators selected him 12th overall in the NHL Entry Draft.
A native of the small village of Stara Lubovna, Hossa went to the Portland Winter Hawks in the WHL before the 1997-98 season and felt right at home. Upon his arrival in Portland, Andrei Podkonicky, who knew Hossa from the Slovak junior nationals, joined him on the team and together they helped Portland capture the 1998 Memorial Cup. Hossa made a second appearance at the World Juniors in 1998 and until then, had had a reputation as a scorer.
In the same season he appeared briefly with the Senators but his next season was delayed by a serious knee injury. In the end, he played 60 games and spent most of his time doing defensive work on the checking line. But when he began scoring goals and collecting points, he seemed to be making up for lost time. He played only two-thirds of the season, but in the voting for the Calder Trophy he came in second after Chris Drury. His solid performance also earned him selection on the NHL All-Rookie Team and once the Senators were eliminated from the post season, he made his second appearance at the World Championships.
Hossa gave the game everything he had. It was becoming clear that Ottawa was offering him the opportunity to be a major player on their team. They started comparing him with Jaromir Jagr, who at the same age conducted himself in a similar manner.
In 1999-00 Hossa tied for the team league in goals with 29 and over the next three seasons topped the 30-goal mark twice and 40-goal mark once. On the internation stage, Hossa went on to represent his homeland for the third time at 2001 World Championships and for the first time at the 2002 Winter Olympics in Salt Lake City.
One of the elite players in the NHL, Hossa went on to finish fifth in leauge scoring in 2003-04 with a career 82 points (36-46-82). Although his NHL season came to an abrupt end in the first round of the Stanley Cup playoffs, Hossa would suit up for Team Slovakia at the 2004 World Championships in Prague, Czech Republic.
In the fall of 2004, Hossa was named to Slovakia's World Cup entry and in the spring of 2005 returned to the World Championship. He found himself on the move from Ottawa after his NHL rights were traded to the Atlanta Thrashers in a blockbuster deal that brought Dany Heatley to Ottawa. In his first season in Atlanta, Hossa tallied 39 goals and added 53 assists for 92 points, easily surpassing his previous point total set in Canada's capital. The following year Hossa made history in Atlanta by becoming the first Thrasher to score 100 points in one season, finishing his year with 43 goals, and 57 assists. In 2007-08, the 29-year-old right was winger set to become an unrestricted free agent, and was unable to come to terms on a contract with the Thrashers. As a result, at the NHL trading deadline Hossa and teammate Pascal Dupuis were dealt to the Pittsburgh Penguins in a blockbuster trade for Colby Armstrong, Erik Christensen, Angelo Esposito and a first-round pick. Coincidentally, both of the Marian and his brother Marcel were traded on the NHL trading deadline on February 26, 2008.
As a member of the Penguins, Hossa's 12 goals and 14 assists in the playoffs helped lead the club to the Stanley Cup Final. The Penguins and Hossa were beat in six games by the Detroit Red Wings, leaving Hossa set to become an unrestricted free agent in the summer.
There was no shortage of suitors for the sniper upon reaching free agency on July 1st, Hossa was offered numerous long-term contracts from various NHL clubs so it was a huge to surprise when Hossa decided to sign a one-year deal with the Stanley Cup Champion, Detroit Red Wings. His assertion being that the club gave him the best chance at winning the Cup in 2008-09.
In the 2008-09 season, Hossa would again find himself in the Stanley Cup Final. This time however he was a Red Wing and his opponent was his former team, the Pittsburgh Penguins. In a twist of fate worthy of Hollywood, the Penguins would upset their former teammate in a hard-fought, 7-game series.
In the summer of 2009, Hossa was once again an unrestricted free agent. This time however he would be looking for much more security than a one-year contract and inked a 12-year deal with the Chicago Blackhawks worth 62.8 million dollars.
The 2009-10 season began with Hossa recovering from off-season shoulder surgery. He would miss almost the entire first two months of the season, but would return with a bang on November 25, 2009 in a game against the San Jose Sharks, scoring twice.
When the Blackhawks completed their sweep of the San Jose Sharks in the Western Conference Final on May 23, 2010, Hossa became the first player in NHL history to reach the Stanley Cup Final in three consecutive seasons with three different teams.
The Blackhawks would defeat the Flyers in six games, winning the franchise's first Stanley Cup since 1961, meaning Hossa would finally get to raise the Stanley Cup. Captain Jonathan Toews passed the cup to Hossa first in the post-game celebration.
Hossa would not have to wait nearly as long for the franchise's next championship. In 2013 the Blackhawks rolled through the NHL's regular season, capturing the Presidents' Trophy, and followed that up in the playoffs. Though pushed to the limit by the Detroit Red Wings in the second round, the Blackhawks would prevail and eventually earn the fifth Stanley Cup title in franchise history.
On October 30, 2014, Hossa recorded his 1,000th career point with a goal against the Ottawa Senators, becoming the 80th player in NHL history to reach the milestone.
Hossa and the Blackhawks would return to the Stanley Cup Final in 2015 where they would defeat the Tampa Bay Lightning in six games. This would make three Stanley Cups in six years.
On October 18, 2016, Hossa scored his 500th career goal, becoming just the second Slovakian-born player to accomplish the feat.
Hossa represented the his homeland on numerous occasions including the Winter Olympics in 2002, 2006, 2010 and 2014.