Bilbo Baggins is 111 years old when he celebrates his famous birthday in J.R.R. Tolkien’s The Fellowship of the Ring.
The birthday party occurs on 22 September, the same date associated with both Bilbo and Frodo Baggins. Bilbo’s unusually long life is presented as one of the remarkable effects of possessing the One Ring, although he is already an unusually old Hobbit by ordinary standards.
At the party, Bilbo gives a speech, uses the Ring to disappear, and leaves the Shire. His departure transfers the Ring’s immediate responsibility to Frodo, setting the central plot of The Lord of the Rings in motion.
The number is sometimes confused with Bilbo’s age when he first meets Gandalf and joins Thorin’s quest in The Hobbit. That adventure begins when Bilbo is 50. His 111th birthday belongs to the later story.