The 35-year-old had been without a club since leaving Palmeiras in November 2020, and after a period of "reflection", the 52-time Brazil international decided to call it quits for good.
Ramires came through the ranks at Joinville before establishing himself with Cruzeiro, where his form earned a move to Europe and Benfica in 2009.
He spent just one season in Portugal before securing a big-money switch to Chelsea, with whom he enjoyed the most successful spell of his career.
Ramires had five and a half years at Stamford Bridge and won every domestic trophy once, while he also won the Champions League and Europa League before departing for Jiangsu Suning of the Chinese Super League.
Announcing his decision in a post on Instagram, Ramires said: "After some time of reflection, I would like to announce that I have decided to officially end my career as a professional football player.
"At this point, I can only thank God first, for he has trained and led me to the highest levels that sport can offer. Thank you very much also to all the clubs I've passed through, Palmeiras, Chelsea, Benfica, Cruzeiro, Jiangsu and Joinville. I will always carry you and your fans in my heart.
"Gratitude also to the Brazilian national team for having provided me the pleasure of playing two World Cups, which was the realisation of a dream.
"I'm thankful also to all the team-mates, staff, coaches and managers that I had the pleasure of working with.
"To my relatives, mother, children, brothers and true friends, thank you so much for being by my side unconditionally all these years, for celebrating each achievement of mine as if it were yours. You've always been my greatest strength and motivation.
"I'm going to go in other directions, but with the same happiness and courage I've had since I was a child, when, against all expectations, I left my city in the interior of Rio de Janeiro to see the world. Thanks for everything, football!"