The 31-year-old left Man United at the end of June when his contract expired, and it was announced at the end of July that he had made the switch to newly-promoted Serie A side Como.
Varane suffered a serious knee injury just 23 minutes into his debut against Sampdoria, and the Frenchman has revealed that he will now be hanging up his boots, but he will remain with Como in a non-playing role.
"They say all good things must come to an end. In my career I have taken on many challenges, rose to occasion after occasion, almost all of it was supposed to be impossible," Varane wrote on Instagram.
"Incredible emotions, special moments and memories that will last a lifetime. Reflecting on these moments, it is with immense pride and a feeling of fulfillment that I am announcing my retirement from the game that we all love.
Varane announces retirement from professional football
"I hold myself to the highest standard, I want to go out strong, not just holding on to the game. It takes a big dose of courage to listen to your heart and your instinct.
"Desire and needs are two different things. I have fallen and risen a thousand times, and this time, it's the moment to stop and hang my boots up with my final game winning a trophy at Wembley.
"I have loved fighting for myself, my clubs, my country, my teammates and the supporters of every team I have played for. From Lens to Madrid to Manchester, and playing for our national team. I have defended every badge with everything I have, and loved every minute of the journey.
"The game at the highest level is a thrilling experience. It tests every level of your body and your mind. The emotions we experience you cannot find anywhere else. As athletes, we are never satisfied, never accepting of success. It is our nature and what fuels us.
"I have no regrets, I wouldn't change a thing. I have won more than I could have even dreamed of, but beyond the accolades and trophies, I am proud that no matter what, I have stuck to my principles of being sincere and have tried to leave everywhere better than I found it. I hope I have made you all proud.
Varane enjoyed a glittering career, winning four Champions League trophies
"And so, a new life begins off the pitch. I will remain with Como. Just without using my boots and shin pads. Something I am looking forward to sharing more about soon.
For now, to the supporters of every club I played for, to my teammates, coaches and staff... from the bottom of my heart, thank you for making this journey more special than my wildest dreams could ever foresee. Thank you, football. With love, Rapha."
Varane started his professional career at Lens before moving to Real Madrid, and he spent 10 years with the Spanish giants before arriving at Man United.
The ex-defender made 360 appearances for Real Madrid before turning out for Man United on 95 occasions, including 32 appearances during the 2023-24 campaign.
Varane has won a host of trophies, including three La Liga titles, four Champions Leagues and the FA Cup during a glittering career, while he was a part of the France team that won the 2018 World Cup and 2020-21 UEFA Nations League.