A close-season arrival on a free transfer, Grandin made just one appearance for the London club, in a League Cup defeat to Bristol City.
The Frenchman, who previously played for Blackpool and Nice, will now have the opportunity to resurrect his career away from Selhurst Park.
A brief statement on Palace's official website said: "Crystal Palace would like to thank Elliot for his services to the club and we wish him all the best for his future career."
Palace winger Jason Puncheon, meanwhile, has hailed the impact of manager Tony Pulis following the club's latest success.
A dismal start to the season left Palace staring at relegation, but Pulis has inspired a dramatic turnaround in fortunes since succeeding Ian Holloway in November and Tuesday's 1-0 victory over Hull City lifted them up to 14th, five points clear of the bottom three.
"I think you can always tell Tony Pulis' teams. He's always very organised and has a great structure to follow," said Puncheon, who has scored the winning goal in Palace's last two matches.
"It was a massive win for us. We knew going into that game (against Hull) it was all about getting three points, no matter how we do it."
