As Louis Smith announces his return to Gymnastics, Newsround looks back at other major sporting comebacks.
Kim Clijsters won 41 WTA singles titles and 11 WTA doubles titles before retiring in May 2007. She returned to the WTA tour for the 2009 and in only her third tournament back won the US Open, becoming the first mother to win a Slam since 1980.
Michael Schumacher is a seven-time Formula One World Champion and is widely regarded as one of the greatest F1 drivers of all time. He retired from racing in 2006 but returned in 2010 to drive for the Mercedes team. His comeback wasn't as successful as some had thought and he retired again in 2012 after three years without a win.
Sir Steve Redgrave is one of Britain's greatest ever Olympians having won five gold medals in rowing. He famously told the BBC in a live interview that he was retiring from rowing, but returned to the boat in 2000 at the Sydney Olympics to claim his fifth Olympic gold and sixth Olympic medal in total.
Michael Jordan has made not one but two comebacks. He retired from basketball at the beginning of the 1993–94 NBA season to pursue a career in baseball, but came back in 1995. He then retired for a second time in 1999, but returned again in 2001 for two more NBA seasons with the Washington Wizards.
Paul Scholes made his full debut for United in 1994 and went on to play a key part in the club's treble-winning success in the 1998–99 season. He has won 11 Premier League, three FA Cup and two UEFA Champions League winners medals. He retired in May 2011 but returned for one season in January 2012 to May 2013
Louis Smith took a break from gymnastics after winning a silver and a bronze medal at the London Olympics in 2012. However, he's now decided that he's going to return to the sport in an attempt to make the England team for the 2014 Commonwealth Games in Glasgow.