Bilbo Baggins’s birthday in J.R.R. Tolkien’s The Lord of the Rings is 22 September.
Bilbo was born on 22 September 2890 of the Third Age, according to the chronology associated with Tolkien’s legendarium. His birthday is central to the opening of The Fellowship of the Ring, where Bilbo celebrates his eleventy-first birthday with a large party in Hobbiton.
The same date is also Frodo Baggins’s birthday. Bilbo and Frodo therefore share a birthday, although they were born in different years. Bilbo’s party provides the setting for his disappearance and for the revelation that he intends to leave the Shire.
A common mix-up is to identify 22 September as only Bilbo’s birthday. Tolkien’s story explicitly gives the date to both hobbits. Tolkien fans also mark 22 September as Hobbit Day, although that modern observance is separate from the fictional calendar itself.