His niece, Emily Atack, confirmed the news on Instagram on Tuesday.
"My wonderful uncle Simon Barnes has been taken from us all so suddenly. The kindest and most talented man you could ever wish to meet. Loved by all who knew him, and will be forever. X," she wrote.
Barnes voiced the role of Tinky-Winky, the purple Teletubby from 1998 to 2001. He also played a role in the children's game show, Incredible Games, as the Dark Knight.
The programme was so popular that it reached a viewership of one billion children in more than 120 countries and was dubbed in 45 languages.
His co-star John Simmit, who voiced Dipsy, the green Teletubby, posted a tribute on Twitter saying, "What a week! RIP Simon Shelton aka Tinky-Winky. Remembering the many good times. Rest easy."
Barnes is survived by his wife and three children. (ANI)