Haywood Knowles Nelson Jr. is an American actor. He is best known for having portrayed Dwayne Nelson in the television series What's Happening!!, which aired from 1976 to 1979, as well as in its spin-off series What's Happening Now!!, from 1985 to 1988.

What's Happening!! is an American sitcom television series that first aired on ABC from August 5, 1976, premiering as a summer series. It returned as a weekly series from November 1976 until its April 1979 conclusion. What's Happening!! was loosely based on the Eric Monte-penned film Cooley High. From 1985 until 1988, a sequel series titled What's Happening Now!! aired in first-run syndication, with most of the major cast members reprising their roles.