Lucas, who earned Kop hero status among supporters, made 346 appearances for the Reds across a 10-year stay on Merseyside.
The 36-year-old had temporarily stepped away from the game after a heart issue was detected during pre-season testing with boyhood club Gremio in December.
The midfielder has now taken the decision to hang up his boots following further examination, confirming his retirement in a press conference on Friday.
As part of a post on social media, Lucas said: "The day has come to say goodbye to the field. I confess that it came from greater forces, but I look back and can only be thankful for the career I built."
He added: “In 2007 I transferred to the giant [that is] Liverpool, which was part of my life for 10 years. It is with great pride that I can say that today Liverpool is my home. I'm proud to be an English citizen and along with my family; I'm Scouser!”
Lucas joined the Reds from Brazilian team Gremio in 2007, with the defensive midfielder working tirelessly to become a fan favourite at Anfield.
He earned a number of caps for his national side and a League Cup winner’s medal in 2012 during his spell – despite missing the final due to long-term injury – and helped Liverpool in their run to the Europa League final in 2016.
Lucas departed Merseyside in 2017, joining Serie A outfit Lazio in Italy – where he spent five seasons, picking up a Coppa Italia winner’s medal in 2019 – before re-joining Gremio in June 2022.
Everyone connected to Liverpool FC would like to wish Lucas the very best in his next chapter.