Nine new episodes of the programme will debut on the streaming service in 2017.
Starring Winona Ryder and Matthew Modine, the first eight instalments follow the search for a young boy who vanishes in small-town Indiana in 1983.
The child’s mother (Ryder) opens an investigation into his disappearance that unravels a series of mysteries involving top secret government experiments, terrifying supernatural forces and a strange little girl.
The second season was announced with an eerie video on Twitter.
It announces that it will be set in 1984 and gives a series of headings including “The pumpkin patch” and “The secret cabin”, leading fans to speculate that they are episode titles.
The horror/sci-fi series was created by brothers Matt and Ross Duffer.