"After this year, there won’t be any more cricket. I'm excited, emotional, happy and certainly not worried because I feel I’ve made the right call," he said at a press conference at the SCG.
The 38-year-old said: "I’m not Benjamin Button. I knew before this season started this would be my last season."
He said he was proud of his two decades at the top level, and nominated receiving his baggy green and playing with brother Shane Lee as highlights.
Lee called time on his international career in July 2012, but has been a Twenty20 regular - both in the BBL and IPL - in the years since.
He remains the equal leading wicket-taker for Australia in one-day internationals alongside Glenn McGrath, with 380 in 221 appearances.
He also claimed 310 scalps in 76 Tests for Australia.
He nominated the 2005 Ashes Test as a career highlight.
Lee's Sixers have one regular-season match remaining, against cross-town rivals the Sydney Thunder, next Thursday at the SCG ahead of a possible finals clash.
Lee said he would be happy to see the Sixers through to the end of the season, but had ruled out a comeback.
"I’m not one of those guys that says – this is it – and comes back in twelve months," he said.
"I’ve got stage two of my life coming up with my family, but there won’t be any comebacks after this."
source - AAP