The 49-year-old "Anger Management" star tweeted a photo with the message, "Happy 11th Sami! What a night!"
Richards, 44, posted pictures of the birthday celebration on Instagram, including a selfie with the whole family.
"Sami's birthday dinner! @Barton_G fun & delish!" it's captioned.
Despite their dramatic past, Sheen and Richards have apparently tried to put their differences aside for the sake of Sami and her nine-year-old sister Lola.
"In the last few years, things have gotten really great with us," Richards told the Huffington Post back in 2013. "We're very close and we're good friends, which is great because it's great for our kids."
"From day one, I've always wanted to keep the kids a priority and suck it up for them, but it takes two people to do that," she added.
Sheen and Richards were married from June 2002 to November 2006.