Back in 1984 she starred opposite Arnie in The Terminator before returning in the even better Terminator 2: Judgement Day, as a more battle-hardened and emotionally-scarred Sarah Connor.
However that was it for Hamilton in the franchise apart from an uncredited voice recording in the ill-fated Terminator Salvation.
Her character has even been played twice since by Game of Thrones stars Lena Headey and Emilia Clarke.
But now, almost three decades later, the 61-year-old Hamilton is back as Sarah for Terminator 6.
Cameron, who was briefly married to the 60-year-old star from 1997-1999, made the announcement at a private event celebrating the Terminator franchise.
He said: “As meaningful as she was to gender and action stars everywhere back then, it’s going to make a huge statement to have that seasoned warrior that she’s become return.
“There are 50-year-old, 60-year-old guys out there killing bad guys [in movies], but there isn’t an example of that for women.”
While both Cameron and Hamilton haven’t been involved in the franchise since 1991’s Terminator 2: Judgement Day, the new movie – simply called Terminator – will be treated as a direct sequel.
Meanwhile Terminator 3, Terminator Salvation and Terminator Genisys will be completely ignored and considered part of an alternate timeline.
Cameron added: “We’re starting a search for an 18-something woman to be the new centrepiece of the new story. We still fold time.
“We will have characters from the future and the present. There will be mostly new characters, but we’ll have Arnold and Linda’s characters to anchor it.”
Terminator will be released in UK cinemas on November 22, 2019.