As played by Martin Freeman.
In a hole in the ground there lived a hobbit. His name was Bilbo Baggins and, like most hobbits, a full pantry and a good book was all that was needed to keep him happy. You may remember him as Frodo's kinsman in The Lord of the Rings, but graduating from a supporting role, Bilbo is The Hobbit's main protagonist. After a wizard and 13 dwarves disrupt his peaceful existence, he embarks upon a most unexpected journey to battle trolls, spiders and dragons to reclaim the dwarves' lost treasure and homeland in Erebor.
Bilbo actor Martin Freeman originally turned down the role due to a scheduling conflict with his BBC series Sherlock; but director Peter Jackson was unwavering in casting Freeman, who he believed to be the perfect Bilbo, and moved The Hobbit's filming date just so Freeman could secure his hobbit hole.