2-time Olympic Gold Medallist / World Championships Gold / 4-time World Championships Silver / Clarkson Cup Champion (2010–11). From 2003 to 2009 Vaillancourt played 88 international games for Team Canada and scored 36 goals adding 39 assists. She won 2 Olympic Gold medals for Canada, in 2006 and 2010. While playing for Harvard University she was named the Ivy League and ECAC Hockey Player of the Year. She led Harvard in scoring, and was ranked fourth overall in the NCAA in 2007–08. In 2008, she won the coveted Patty Kazmaier Award.
Vaillancourt started skating at the age of two years and a half and playing hockey at five years. She made the national team when she was 18 and one of her favourite hockey moments is winning gold on home soil at the Vancouver 2010 Olympic Games. She studied psychology at Harvard University and works as a skills coach. Vaillancourt is openly lesbian.
Vaillancourt was the captain of Canada's under-22 team at the 2007 Air Canada Cup. In 2003, she was the captain of Team Québec at the Canada Winter Games that won the silver medal. One of her teammates was future Olympian Catherine Ward. She graduated from high school as a tri-varsity captain and athlete from Pomfret School in Pomfret, Connecticut, as a member of the class of 2004.
She was a star for the Harvard Crimson women's ice hockey program and won the Patty Kazmaier Award in 2008. Her freshman year was in 2004–05, and she finished fifth in the nation, and first among freshmen, in scoring with 2.31 points per game.
In 2005, she made the Canadian national women's hockey team, where she would go on to play at the 2005 Women's World Ice Hockey Championships in Sweden. In her first game ever, she led Canada with 6 points in an 13–0 win over the Kazakhstani national women's ice hockey team. This tied a record for most points in a game on the Canadian national team. She would finish the tournament with 8 points. On February 20, 2006, Vaillancourt, as the second youngest member of the team, won a team gold medal in Turin with the Canadian women's hockey team beating Sweden in the final game and outscoring their opponents 46 to 2.
At 2010–11 season, Vaillancourt joined the Montreal Stars mid-way through the season and instantly become a fan favourite, managing to crack the league's top-10 leading scorers, with an impressive 28 points (11 goals and 17 assists) in only 15 games. In the championship game of the 2011 Clarkson Cup, Vaillancourt scored a goal in the third period. By winning the 2011 Clarkson Cup, Vaillancourt became an unofficial member of the Triple Gold Club (the accomplishment by women is not yet officially recognized by the IIHF), as she became one of only four women to win the Clarkson Cup, a gold medal in the Winter Olympics, and a gold medal at the IIHF World Women's Championships. The other women include Caroline Ouellette, Jenny Potterand Kim St-Pierre. Surgery in the left hip held her outside the action this 2011–12 season.
|2005 Women's World Championships||5||3||5||8||2|
|2007 Women's World Championships||5||2||4||6||4|
|2008 Women's World Championships||5||4||2||6||8|
|2009 Women's World Championships||5||3||4||7||8|
- 2004-05 All USCHO.com Rookie Team
- Top 10 Finalist for 2007 Patty Kazmaier Award 
- First Team All-Ivy League, 2007–08, Harvard (junior), unanimous selection
- Ivy League Player of the Year 2007-08, Harvard (junior), unanimous selection
- 2009 First Team All-Ivy League
- Sarah Vaillancourt, 2009 First Team All-ECAC 
- 2009 ECAC Player of the Year 
- 2011 Clarkson Cup Tournament Most Valuable Player[