The former Liverpool defender, who made 62 senior appearances for the Reds primarily at right-back, joined Palace in 2014.
He would spend the next eight years of his career in South London, making 34 appearances in his first season at Selhurst Park as the Eagles finished 10th.
Perhaps the highlight of his time at Palace came the following season. Kelly's first goal for the club proved to be the winner in a memorable FA Cup quarter-final triumph away at Tottenham, with the team going on to reach the final that season.
Kelly, who also represented England at Under-21 level, left Palace following the expiration of his contract in 2022, having made 148 appearances in all competitions.
The 35-year-old would later play for West Bromwich Albion and have a brief spell at Wigan Athletic on loan.
Kelly told The Athletic: “I’ve never actually got around to writing the social media post to announce it; I’ve only told friends and family, but yeah, I’ve retired.
“It was March when I sat down with the family and told them I was thinking about it. Around the same time, I got asked to play for Liverpool in a legends game against Chelsea. One of the stipulations was that you had to be retired, so that just reaffirmed my decision.”
Everyone at Crystal Palace wishes Martin well for his next chapter.