The 25-year-old defender has signed a two-year contract, with the option of an extra year with the Addicks.
Inniss stated: "I want to thank the club for the faith they've shown in me throughout these 10 years, and a special thank you to the people who have helped and supported me through some tough times on and off the field.
"I'd also like to thank the managers who I've had the pleasure of working with during my time at Palace. The opportunity to play with the first-team this season will be a memorable one - not just because of the number of penalties(!), but because it showed me how capable I am of performing at this level, and gave me a big confidence boost which I'll be able to take into this next chapter of my career.
"I'm sad to be saying goodbye, but I know it's the right time for me to move on."