Her death was unexpected. Henderson had not been sick, her manager, Kayla Pressman, said. Just this week, Henderson attended a taping of ABC's "Dancing with the Stars" to cheer on Maureen McCormick, who played her TV daughter Marcia Brady.
Henderson had made some TV and movie appearances this year.
"We are all in a state of shock," said Pressman, who spoke with the actress Wednesday night. Henderson died in a Los Angeles hospital, surrounded by family and friends.
Henderson played Carol Brady from 1969 to 1974 on "The Brady Bunch," a show that became a huge hit in syndication.
"The Brady Bunch" was a story about a lovely lady and a man named Brady, a widow and widower with three children each.