Alton Towers Resort announced the closure on social media on September 21.
The rollercoaster in question is arguably one of the park's most famous rides - the legendary Nemesis.
Nemesis was Europe's first inverted rollercoaster and has been exciting thrillseekers since 1994 with its "corkscrews, spins and loops," according to the Alton Towers website.
"Experience 3.5 G-force as you race past the rocks and rivers of the Forbidden Valley at 50mph," the theme park's description says.
Nemesis will be closing down on November 6, giving fans just over a month to ride the famous rollercoaster.
The Alton Towers Facebook post read: "By order of the Phalanx, Nemesis is closing.
"You have until 6th November to ride. Please make your way to Alton Towers Resort in an orderly fashion."
Signs like the above image have reportedly been seen by visitors around the park too.
However Nemesis will be reopening following a revamp.
No one knows what the new-and-improved rollercoaster will look like but it's reopening in 2024.
"Nemesis, Europe’s first inverted rollercoaster will return in 2024 after an exciting revamp," Alton Towers said.
"Until then, visitors to the theme park will have just a few more weeks to enjoy its corkscrews and loops before it starts its transformation this winter."
If you want to ride Nemesis in its current form before it closes, you can book tickets at: www.altontowers.com/tickets-passes/
Alton Towers have been contacted for comment.