Between 1999 and 2011, Nichols lived in St. John's, Newfoundland and Labrador, where he played third for the Brad Gushue rink. It was with Gushue that he represented Canada at the 2006 Winter Olympics. With Gushue, Nichols has been to three Canadian Junior Curling Championships (1999, 2000, and winning in 2001) and fourteen Briers (2003-2005, 2007-2011, 2015–2020). He also qualified for the 2013 and 2014 Brier with Manitoba's Jeff Stoughton rink. He also won the World Junior Curling Championships in 2001 with Gushue. He also won Gold in the 2006 Winter Olympic Games in Turin, at which he threw a spectacular shot - running back a guard onto another stone which picked another rock that was sitting in a dead zone - in the 6th end of the final against Finland, helping Canada to score 6. Certainly, one thing to aid their victory was the fact that Nichols shot a blistering 97 percent in the gold medal final. "When he’s playing that way, we don’t lose very much," said Gushue.[6] He is also the 2017 Tim Hortons Brier Champion, again as third for Gushue, defeating Kevin Koe 7-6 in the final, helping Gushue to win the Brier in his 14th appearance. This was an especially sweet victory for Nichols, who had lost 3 Brier finals previously- with Gushue to Glenn Howard in 2007, with Stoughton to Brad Jacobs in 2013, with Gushue to Kevin Koe in 2016. The 2017 Brier was also in St. John's, where the Gushue team is from. The team went undefeated at the 2017 World Men's Curling Championship, defeating Niklas Edin in the final. At the 2018 Brier, he went back-to-back as brier champion, but this time he was a member of Team Canada, defeating Brendan Bottcher of Alberta 6-4 with fellow skip Brad Gushue. At the 2018 World Men's Curling Championship, they would lose the final in a rematch against Sweden's Edin. They couldn't win three Briers in a row, losing the 3 vs. 4 game of the 2019 Tim Hortons Brier to Brendan Bottcher.
He briefly retired from curling after the 2011 Brier, although he always suggested he might return at some point, which he did for the 2012-2013 season as Jeff Stoughton's lead. He would play two whole seasons with Jeff, winning a silver at the 2013 Brier, and in the middle of the 2013-2014 season, moved to throwing second stones for Jeff, missing the playoffs at the Canadian Olympic Trials, but winning a bronze at the 2014 Brier. He left the Stoughton rink to reunite with Brad after the 2014 Brier.
He won the Ford Hot Shots shot-making competition at the 2005 Brier, winning a two-year lease on a new Ford vehicle.
In 2005, he graduated with a Bachelor's degree in Kinesiology from the Memorial University of Newfoundland. He also received an honorary Doctor of Laws degree in 2006 and received a certification of Mac-Nutrition in 2021.[4]
With Gushue, Nichols is the co-owner and personal trainer with Orangethory Fitness in St. John's.[12] In the summer of 2011, Nichols married his longtime girlfriend and fellow curler Colette Lemon. They have two children.[13] In August 2011, Nichols ran for the Progressive Conservative nomination in the district of Labrador West, losing to Nick McGrath.[14][15] His mother, Helen competed for Newfoundland at the 1992 Scott Tournament of Hearts.[4]
