Which Tolkien character owns Bag End at the beginning of The Hobbit?

Bilbo Baggins owns Bag End at the beginning of J.R.R. Tolkien’s The Hobbit.

Bag End is Bilbo’s comfortable hobbit-hole in Hobbiton, a settlement in the Shire. Bilbo enjoys a quiet life until the wizard Gandalf arrives with Thorin Oakenshield and a company of dwarves. Their visit draws him into the quest to reclaim the Lonely Mountain and its treasure from the dragon Smaug.

Bilbo later adopts his cousin Frodo as his heir and leaves Bag End after his eleventy-first birthday party. Frodo becomes the central hobbit of The Lord of the Rings, while Bilbo remains an important earlier link in the history of the One Ring. Bag End is often confused with Frodo’s home because Frodo lives there for much of the later story, but Bilbo is its owner at the opening of The Hobbit.