Career beginnings

Eriksson began curling before he was six years old. He followed his older brothers Anders Eriksson and Markus Eriksson into the sport, but his skill level advanced more rapidly.^[3] He was part of a curling team at age seven,^[3] debuting in Sweden's Elite Series at the age of thirteen.^[5] He won his first Swedish Men's Curling Championship title in his junior career and has gone on to win six more championship titles since then.^[6] As a junior, Eriksson also competed at three World Junior Curling Championships, winning both a gold medal and a silver medal. At those three World Junior Championships, Eriksson skipped two different Swedish teams, winning a total of 24 games and losing only 9.

Eriksson made his first run for a junior world championship title when he was sixteen at the 2008 World Junior Curling Championships, skipping his first team to a silver medal. The team, consisting of Henric Jonsson, Markus Franzén, and Nils Karlsson, lost in the final to the US team skipped by Chris Plys. In 2008, Eriksson moved to Härnosand to join other promising curlers at Härnosands gymnasium.^[7] He also joined Team Lit/Lindström, formed by brothers Kristian Lindström and Alexander Lindström, together with Christoffer Sundgren and Henrik Leek. The team immediately succeeded on the junior tour and scored wins in the senior division.^[7][8] With this team, Eriksson made his second run for the gold medal at the 2009 World Junior Curling Championships, but finished in fourth place, losing in the bronze-medal game to the US team that was again skipped by Plys. Though the team did not qualify to compete at the championships in 2010,^[9] Eriksson and his teammates finally won a gold medal at the 2011 World Junior Curling Championships, defeating Team Switzerland, skipped by Peter de Cruz, by a score of 6–5 in the final.

By 2012, Eriksson's Lit teammates were no longer eligible for junior competition, but Eriksson was still eligible for junior championships. He skipped Team CK Granit-Gävle, consisting of Ludwig Grann, Erik Ölund, and Magnus Rudström, at the 2012 Swedish Junior Curling Championships with the aim of qualifying for the World Junior Curling Championship. Eriksson's team was undefeated until the finals, but there they came in second place to the team from Sundyberg, skipped by his future teammate Rasmus Wranå,^[10] whose team won silver at the 2012 World Junior Curling Championships.

Seniors I (2008–2014): Team Lindström/Eriksson and Team Edin

Shortly after joining Team Lit in 2008, Eriksson played simultaneously with two teams. His official team during this period was Team Lit, alternatively known as Team Lindström and eventually Team Eriksson. Eriksson skipped the team for most of this period through 2014.^[11][12] In addition to their early tour successes, Team Lit finished second in the standings of the Swedish Men's Curling Championships in 2009, reaching the semifinals,^[13] and finished second in their group Division 1 of the Elite series the same year.^[14] He competed with a second team, however, from 2009 through February 2014, as he was selected as the alternate for Team Niklas Edin – with Niklas Edin, Sebastian Kraupp, Fredrik Lindberg, and Viktor Kjäll – in all of their international championship appearances. As part of Team Edin, he competed in three World Curling Championships (2011-2013), five European Curling Championships (2009-2013), and the 2010 and 2014 Olympic Games. During this period, however, Team Lit became more competitive with Team Edin and was well recognized as one of the top two men's curling teams in Sweden.^[15] While Team Lit came in second to Team Edin in the Elite Series from 2011-2013,^[16][17][18] Team Lit also won the Swedish Men's Curling Championship in 2011, 2013, and 2014.

As an alternate for Team Edin during this period, Eriksson received numerous international medals, including two gold medals at the European Curling Championships (2009 and 2012) and three World Curling Championship medals, including his first World Championship gold medal (2013) and two bronze medals (2011 and 2012). He played his first full games at a major championship in the senior division at the 2011 European Curling Championships in the final two round-robin draws.^[19] At the 2012 World Men's Curling Championship, however, he notably played in the second position for all games except three because Niklas Edin, the permanent skip, was suffering from a herniated disc in his back. Eriksson also played this position in the playoffs, in which Team Sweden won its second World Curling Championship bronze medal. At the 2013 European Curling Championships, he also curled for a third of the round-robin games, playing the second position in the seventh and eighth draws and the third position in the final draw, helping the team secure a winning record, despite not making the playoffs.^[20] He also made his first Olympic appearances with Team Edin, coming in fourth in the 2010 Winter Olympics and receiving a bronze medal in the 2014 Winter Olympics.

With his own team, however, Eriksson and his teammates won several international events, including the Oslo Cup (2009), Swiss Cup Basel (2012), and European Masters (2013), as well as the Winter Universiade (2013).^[12] In 2012, the team had also relocated to Karlstad, with Markus Eriksson joining the team, following the departure of Leek and Alexander Lindström, and they continued to expand their international competition aims. In the 2013-14 season, Team Eriksson reached second place at the Swiss Cup Basel and the Mercure Perth Masters and competed in Canada on the World Curling Tour, coming in fifth place in three events and reaching their first Grand Slam Quarterfinal at the National.^[12] Winning the Swedish Men's Curling Championships that year as well, the team was selected to represent Sweden in the 2014 World Men's Curling Championship in light of their season success, but also because Team Edin had represented Sweden in the European Curling Championships but had not qualified for the playoffs.^[21] In their World Curling Championship debut, Team Eriksson reached the final and won the silver medal.

Seniors II (2014–present): Team Edin

In May 2014, Edin and Team Eriksson agreed to form a new Team Edin, with Edin skipping the team in the fourth position and Oskar Eriksson playing third along with, Kristian Lindström playing second and Christoffer Sundgren in the lead position.^[22] From the start, this new Team Edin team immediately saw their increased potential and aimed to become the number one team in the world.^[22] When Lindström underwent surgery in 2016 and needed recovery, however, Rasmus Wranå began curling in the second position for the team.^[23] With all four players having experience as skips, the Team had rapidly increased success. Indeed, Team Edin was ranked first at the end of the 2016–17 curling season on both lists and finished in first place on the prize money list in the 2017-18 curling season.

With Team Edin, Eriksson has earned multiple major championship medals since the 2014-15 season. At the 2022 Olympics, the team won their first gold medal, winning the silver medal in 2018, and Eriksson and Edin also secured bronze medals under the original Team Edin in 2014. These Olympic medals are the only Olympic medals in men's team curling that Team Sweden has won since the inaugural event in 1924. The team also reached the finals of the European Curling Championships every year since forming a new team, winning gold five times (2014-2017 and 2019) and silver twice (2018 and 2021). Of most significance, perhaps, the team secured medals in the finals of the World Curling Championships every year except 2016, winning five gold (2015, 2018, 2019, 2021, and 2022) and one silver (2017), bringing the total for Edin and Eriksson to a record six World Championship gold medals.

Since the 2014-15 season, Eriksson and his teammates have consistently ranked in the top ten teams in the world since they joined forces due to their performance in Canada and worldwide. The team has reached the playoffs in 30 Grand Slams of Curling Events, 25 of them achieved since Wranå joined the team. Indeed, in the 2016-17 season, Team Edin had their most successful year on tour, winning three Slams (the Masters, the Tour Challenge, and the Players’ Championship) and reaching the finals (the Canadian Open) and semifinals (the National and Champions Cup) of all but one of the slams, securing the Pinty’s Cup, the first non-Canadian men's team to do so. The team finally won their fourth Slam at the 2022 Tour Challenge, with Eriksson skipping the team in the semifinal and final when Edin was injured. The Team has also won several World Curling Tour events, including the Baden Masters (2015, 2017, 2020), Swiss Cup Basel (2016, 2018), Curling Masters Champery (2016, 2017), Perth Masters (2018), and European Masters (2014).^[12] Team Edin has also won the Swedish Men's Curling Championships six times between 2014 and 2020, skipping only the 2017 championships to prepare for the World Championships.

Mixed events

Eriksson also currently competes in mixed doubles curling and has formerly competed in mixed curling. In mixed curling, his most successful run at the Swedish national championships occurred in 2008, where his team – consisting of Christoffer Sundgren, Maria Östman, and Marina Stener – reached second place, losing to the team of Niklas Edin, Anette Norberg, Eric Carlsén, and Anna Hasselborg.^[24] His last appearance in the Swedish national mixed championships was in 2012 when he curled with Hasselborg, Kristian Lindström, and Marina Stener.^[25] Since then, outside of playing men's team curling, he has participated mostly in mixed doubles. He has continued to play mixed curling, primarily in the Continental Cup.

Eriksson's longest-running mixed doubles partnership is with Anna Hasselborg, with whom he began curling at Härnosands gymnasium.^[26][27] The pair went on to compete in the Swedish Mixed Doubles Curling Championship four times, winning the event each time that they entered (2013, 2016, 2017, and 2019). Despite Hasselborg and Eriksson's victories, longtime mixed doubles specialists Per Noreen and Camilla Noreen were selected to represent Sweden in the World Mixed Doubles Curling Championships in 2016 and 2017, but unfortunately were unable to earn Team Sweden a spot in the Olympic mixed doubles event. In 2019, however, Hasselborg and Eriksson were selected to represent Sweden in the 2019 World Mixed Doubles Curling Championship, where they won the gold medal over Team Canada in their championship debut. In 2019, they also won their first career mixed doubles tour event at the MadTown DoubleDown mixed doubles tournament.^[28]

In the 2020-21 season, the Swedish Curling Association launched a substantial effort to prepare for the 2021 World Mixed Doubles Curling Championship and to qualify for the 2022 Olympics, supporting five teams on the mixed doubles tour. Eriksson was selected for one of the teams, partnering with Almida de Val, as Hasselborg chose not to participate in mixed doubles during the 2020-21 curling season. Eriksson and De Val won their first event as a team at the Oberstdorf International Mixed Doubles Cup in September 2020,^[29] then reached the quarterfinals of the Mixed Doubles Bern championship.^[30] In 2021, Eriksson and de Val won the Swedish Mixed Doubles Curling Championship,^[31][32] giving Eriksson the distinction of being the only Swedish curler to win the national mixed doubles title five times.^[33] On March 1, 2021, the Swedish Curling Association formally announced the selection of Eriksson and De Val to represent Sweden at the 2021 World Mixed Doubles Curling Championship.^[34][35] Eriksson and de Val were undefeated in the preliminary rounds and after a tight loss in the semifinal won the bronze medal, defeating Kerri Einarson an Brad Gushue.^[36] At the conclusion of the season, Eriksson and de Val were chosen to represent Team Sweden in mixed doubles at the 2022 Winter Olympics.^[37]

In the 2021-22 season, de Val and Eriksson played the Aly Jenkins Mixed Doubles Memorial tournament, reaching the semifinal, where the victors were the event champions, Isabella Wranå and Team Edin second Rasmus Wranå.^[38] In December 2021, Eriksson and de Val competed in the Gothenburg Mixed Doubles Cup and finished first in the overall standings heading into the playoffs, ultimately winning the silver medal in the tournament.^[39] In preparation for the Winter Olympics, De Val and Eriksson had completed an intense training season under controlled conditions, but when one of their coaches tested positive for COVID-19, their arrival in Beijing was delayed until the day before the competition.^[40] After an extremely competitive round-robin program, Eriksson and De Val finished in fourth place, losing in the semifinals to Italy but defeating Great Britain to secure the bronze medal.^[41]