Viktor Ahn, Marit Bjørgen, and Patrick Chan were some of the other stars to end their career this year.
The Olympic year is over and after the successes of PyeongChang 2018 and Buenos Aires 2018, it's time to look back at those the world of sport bid farewell to this year.
Some did so after the Winter Olympics in South Korea, while others ended their careers at the end of the summer sport season.
Here we pick out a few of the Olympic champions who retired from competing this year.
Julien Absalon announced he was ending his cycling career in May, saying that a worsening pollen allergy prevented him from continuing at the top level.
"I couldn't breathe properly and could taste blood," he told L'Équipe.
The 38-year-old tasted Olympic Games victory twice in mountain bike cross-country.
His two golds came at Athens 2004 and Beijing 2008.
Absalon crashed out of the London 2012 race, and finished eighth in his final Olympic appearance at Rio 2016.
The Frenchman also clinched five World and five European championships during his career.
Short track great Viktor Ahn, also known as Ahn Hyun-soo, won six golds during his career.
The native of Seoul, South Korea, made his debut at Salt Lake 2002 when he finished fourth in an incredible race won by Australia's Steven Bradbury, before going on to win three golds at Torino 2006 for his birth country.
But after being overlooked for the 2010 Olympic team, he switched to represent Russia in time for the 2013 season, going on to win three more golds at a home Games in Sochi.
Ahn had hoped to end his career in PyeongChang, but was not approved to compete as an Olympic Athlete from Russia by the Court of Arbitration for Sport.
He retired in September, and declined an offer to become a Russian coach.
Norway's Marit Bjørgen called it a day after PyeongChang 2018, during which she became the most-decorated Winter Olympian ever.
The 38-year-old won two golds, a silver, and two bronzes in South Korea to take her tally to an incredible 15 Olympic medals — eight of them gold — won across five Olympic Games, starting at Salt Lake 2002.
She also won 18 World Championship titles during her career, and finished top of the World Cup podium on 143 occasions.
When Marit Bjørgen broke the record for most Olympic Winter Games medals won by an individual, she surpassed a mark set by her compatriot Ole Einar Bjørndalen, who won 13 Olympic medals during his career.
Bjørndalen was named on six Olympic Games squads in his career, making his debut in his home Games of Lillehammer 1994.
In addition to competing in biathlon, he also finished fifth in 30 km freestyle cross-country skiing at Salt Lake 2002.
During his 25-year career, he won eight Olympic golds and 20 World Championship titles.
The 44-year-old finally called it quits in April this year, after struggling on the World Cup series and failing to make the Norwegian team for PyeongChang.
A 24-year-old Cameron van der Burgh became the first man from his country to clinch an individual swimming gold when he broke the 100m breaststroke world record at London 2012.
The South African won silver four years later in Rio.
Now 30, van der Burgh left the sport with two long-course and four short-course World Championship titles, winning his last two this year in Hangzhou, China.
He also claimed four Commonwealth Games and six African Games golds during his career.
A double silver medallist at Sochi 2014, it seemed like Patrick Chan would end his career without an elusive Olympic gold.
The most-decorated Canadian figure skater ever, Chan finally became an Olympic champion when Tessa Virtue and Scott Moir clinched gold for Canada in the team event at PyeongChang 2018.
Chan, a three-time Olympian, also won the World Championship three times, the Four Continents Championship three times, and the ISU Grand Prix Final twice during his career.
The 27-year-old confirmed his retirement in April.
Missy Franklin burst onto the world stage by winning four golds aged just 17 at London 2012, but then struggled with injuries and her mental health.
Franklin, who won a relay gold at Rio 2016, also shared her struggles with mental health problems on the Olympic Channel podcast earlier this year.
"Going into Rio I almost felt like I had failed before it even began because if I somehow didn't live up to that same performance I gave in 2012, it would be a disappointment.
"I really went in there with other people's goals. And that's not why I do this, that's not why I swim and that's not who I am.
"There were some really really tough times and times that I thought I would never get into the pool again."
Hungary had a new swimming sensation on their hands when Daniel Gyurta, then just 15, surprised everyone to win 200m breaststroke silver at Athens 2004.
Eight years later in London, Gyurta went one better, breaking the world record en route to winning gold.
Gyurta also won five world championship golds (three long-course and two short-course) during his career, and eight European titles.
The 28-year-old, who remains a member of the IOC Athletes' Commission, retired in March.
Germany's Robert Harting is perhaps remembered more for his wild celebrations after winning gold at London 2012 than his actual gold medal performance in the Olympic Stadium.
The discus thrower, then 27, ripped off his vest after being confirmed as Olympic champion before grabbing a German flag and jumping over the hurdles that were in place on the running track for the hurdles race.
A three-time world champion from 2009 to 2013 and a two-time European champ, injuries finally took a toll on the athlete, who retired in September.
His younger brother, Christoph Harting, succeeded him as discus Olympic champion.
The most-decorated female American Olympic skier when she retired in January, Julia Mancuso found that her body simply couldn't keep up with the demands of top-level racing any more.
Mancuso won gold in the giant slalom at Torino 2006, before adding two silvers in Vancouver and a bronze in Sochi.
She attempted to make a fifth Olympic team for PyeongChang, but the then-33-year-old struggled during the World Cup season, and decided to end her career in January in Cortina d'Ampezzo, Italy, where she clinched her first World Cup podium.
Double Olympic champion Petter Northug announced his retirement in mid-December after failing to recover from a long-term injury in time for the new World Cup season.
Northug won gold in both the team sprint and 50 km classical races at Vancouver 2010, in addition to a silver and a bronze medal.
But the 13-time world champion, struggling for form heading into Sochi 2014, returned from Russia empty-handed.
His career was sidetracked later that year after he was found guilty of drink-driving and sentenced to 50 days in prison and a fine.
The last time Northug won one of his 38 career World Cup wins was in 2016, and he failed to make the PyeongChang 2018 squad after suffering from illness shortly before the selection deadline.
Northug's 13 World titles make him the most successful men's cross-country world championships skier ever.
American-born Pete Reed won three golds in rowing for Great Britain while juggling a military job during his sporting career.
The Lieutenant Commander in the Royal Navy made his debut at Beijing 2008 as part of the coxless four.
Reed then defended that title four years later on Dorney Lake at his home Games of London 2012, before moving into the bigger coxed eight boat for Rio 2016 and winning his third Olympic title.
Although the naval officer had intended to continue on to Tokyo 2020, hip surgery in 2017 and a failure to regain top form led the 37-year-old to call it quits in April.
One-third of Great Britain's three Olympic track and field champions on so-called "Super Saturday" at London 2012, long jumper Greg Rutherford retired in September after an appearance at the Great North City Games in Newcastle.
The 32-year-old won the second of Britain's three athletics golds on 4 August 2012, between Jessica Ennis-Hill's heptathlon triumph and Mo Farah winning the 10,000m.
He added Commonwealth Games and European Championship gold medals in 2014 before winning the world title in Beijing a year later, becoming just the fifth Briton to have won titles in all major international meets.
Rutherford defended his European title in 2016 before taking Olympic bronze in Rio.
Injuries took their toll later in his career, and Rutherford was unable to mount a second defence of his European crown in Berlin earlier this year.
However, while he's done with athletics, don't be surprised if you see him in a different sport soon.
British athletes have won three Olympic gold medals in a row in women's skeleton.
Lizzy Yarnold was responsible for two of them, as she became the sport's first double Olympic champion at PyeongChang 2018.
Yarnold's success in South Korea, four years after her triumph at Sochi 2014, also made her the first Briton to successfully defend a winter Olympic title.
She was also Great Britain's flagbearer at the Opening Ceremony in PyeongChang.
However, an issue with dizzy spells and vertigo suffered in Korea, combined with knee and back surgeries, ultimately led Yarnold to retire in October.