Apparently in 1998.
https://en.m.wikipedia.org/wiki/Dave_Chappelle
Chappelle lives with his wife, Elaine Mendoza Erfe,[3] sons Sulayman and Ibrahim,[37][59] and daughter Sonal on a 65-acre (260,000 m2) farm[1][14] near Yellow Springs, Ohio.[35]
Chappelle converted to Islam in 1998. He told Time in May 2005, “I don’t normally talk about my religion publicly because I don’t want people to associate me and my flaws with this beautiful thing. And I believe it is beautiful if you learn it the right way.”[28][61]
Wow...incredibly disappointing. :/