Wagner was the only original cast member still in the soap
US actress Helen Wagner, best known as Nancy Hughes in the CBS soap opera As The World Turns, has died aged 91.
CBS said she had died on Saturday, but gave no further details.
Wagner spoke the show's opening words when it first aired in 1956. She holds the Guinness World Record for playing the same TV role for the longest time.
Wagner still featured in the show when it was announced in December it would be cancelled later this year. The last episode will go out in September.
In 1988, Wagner said in an interview that she wished her character had not receded into the background in later years.
"I don't like the making of Nancy into only an extra figure at parties," she said.
"She is too dynamic a person to be made into a ghost."
The show was the first TV daytime drama to run for half an hour rather than 15 minutes, and was expanded to an hour in the 1970s.