Sesame Workshop says Nelson, who suffered from emphysema, died Thursday night in his Massachusetts home on Cape Cod. He was 78.
A tribute to Nelson was posted on the educational workshop's website. It lauds Nelson for his artistry and the "laughter he brought to children worldwide" with the count and other Muppet characters, including Herry Monster and the Amazing Mumford.
Nelson also performed characters on the "Fraggle Rock" show, including Gobo Fraggle.
In recent years, Nelson stopped operating the Count and other "Sesame Street" puppets but still served as their voices.
The workshop says the new season of Sesame Street launches next month and Jerry Nelson's voice will be heard.