Every year, the Tolkien society encourages fans around the world to celebrate the day the much-loved author was born.
Fans are asked to simply raise a glass at 9 p.m. local time, and say "The Professor".
There have also been gatherings taking place all around the world.
Tolkien was born in 1892, and was a Professor of Anglo-Saxon (Old English) at Oxford University.
The idea for Tolkien's beloved world came when he was marking a student's exam paper.
A student had left an entire page of an exam blank, and Tolkien – for reasons unknown – wrote, "In a hole in the ground there lived a Hobbit."
The Hobbit was eventually published in 1937.
Peter Jackson has recently said there won't be any more Tolkien films due to legal issues.
Other works that have not been filmed include The Silmarillion and Unfinished Tales of Númenor and Middle Earth.
Here's to you, Professor!
Alan White is a news editor for BuzzFeed News and is based in London.
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