Cavendish has competed in 13 editions of the Tour de FranceMark Cavendish, one of Britain's most successful cyclists, will retire at the end of the season.
In 2021 he equalled the legendary Eddy Merckx's record of 34 Tour de France stage victories.
During a news conference at the Giro d'Italia, Cavendish, 38, said: "Cycling has been my life for over 25 years.
"It's taught me so much about life, dedication, loyalty, sacrifice and perseverance - all important things to pass on now as a father."
He added: "The bike's given me opportunities to see the world, meet incredible people who are involved and not involved in the sport - a lot of whom I call friends.
"Today it's my son Casper's fifth birthday; it's a rest day and I can spend that with them now. Now it's important to be there for every birthday, every school concert - important I can be there for them."
The glittering career with a fairytale ending
Cavendish enjoyed a glittering career as a sprinter, taking victories on the flatter, faster stages of races, particularly in the Grand Tours.
He has won 161 races since 2005 and two green points jerseys at the Tour.
Cavendish's other major achievements include an omnium silver medal at the 2016 Rio Olympics, the 2011 Road World Championships rainbow jersey, the 2009 Milano-San Remo 'monument' one-day classic, 16 stage wins in the Giro and three in the Vuelta a Espana.
He is currently riding for Astana Qazaqstan in the Giro, which ends in Rome on Sunday.
Cavendish experienced injury and illness from 2017, hinting at the end of the 2020 season that he could retire.
But following a return to form the following year he won four more Tour stages and the green jersey in his second spell with the successful Quick Step team, who helped reinvigorate his career.
Cavendish and his family were the victims of a violent robbery at their home in 2021.
He was omitted from Quick Step's Tour squad the following year, after which he signed for Astana Qazaqstan for 2023.
He will attempt to break the Tour stage win record at this year's race, which begins in Bilbao, Spain, on 1 July.
He added: "This is a perfect opportunity to say with absolute joy in my heart that this will be my final season as a professional cyclist.
"Right now there's no need to talk about my short- and long-term plans - I'll always be a cyclist, that's for sure.
"But for this final period I'd like to just enjoy doing what's made me happy for the last 25 years, and that's simply to race."
Cavendish's early career saw him competing for the Isle of Man on the track at the Commonwealth Games, winning gold in the men's scratch race in 2006The Manx Missile
Cavendish, from the Isle of Man, showed promise as a BMX and mountain bike rider, and was then part of the new era of investment in cycling in Britain, which saw British Cycling dominate track cycling at the 2008 and 2012 Olympics.
Cavendish began his professional career in 2005 in a feeder team for T-Mobile, winning his first Tour stage in 2008 for Team Columbia.
He was known throughout his career as the 'Manx Missile' on account of his blistering finishing speed during bunch sprints.
At 5ft 7in, he has a low centre of gravity and can adopt an aerodynamically advantageous position on the bike during powerful bursts of speed.
Cavendish dominated sprinting for many years and is considered a big influence on younger riders across the peloton, including new British talents such as Quick Step's Ethan Vernon.
I want to see my kids grow up - CavendishCavendish is known to have a fiery persona on and occasionally off the bike, and during the 2021 Tour he was filmed berating a team mechanic before a stage.
Former Quick Step coach Tom Steels told BBC Sport last year: "When he steps out of the team bus you never know if he'll come back in five minutes like a wild bull because something is wrong with the bike.
"But you can always talk with him and once it's fixed it's over. It's not ever personal, but you never know how he can react."
Cavendish is immensely popular in the peloton and fiercely defends fellow riders who come in for criticism.
British Cycling performance director Stephen Park said: "Cav is without doubt the sport's greatest sprinter and will be remembered by fans across the world for his 53 Grand Tour stage wins.
"What most stands out in Cav as a sportsperson is the overwhelming sense of pride he showed each time he pulled on both the Great Britain cycling team and British national champion's jerseys - a quality we want to instil in every single member of our team."
