The seventh series will air in the UK on 17 July, a day behind American viewers, and it'll be the penultimate series.
Fans watched an online video for more than an hour to see a huge block of ice being melted to reveal the air date.
It's thought the post was nodding to the series title: A Song of Ice and Fire
A new trailer was released for the show too.
In it, Jon Snow says: "There is only one war that matters. The Great War. And it is here."
According to broadcasters, the coming series promises a "brutal, bloody and wintry return to Westeros".