The Golden Oak Library is a stocky hollowed-out tree and the home of Twilight Sparkle,Spike, and Owlowiscious in seasons one through four. In Twilight's Kingdom - Part 2, the aboveground portion of it is destroyed by Lord Tirek and Princess Twilight subsequently gains her own castle as part of her Friendship Rainbow Kingdom. The main reading room is on the ground floor, while the bedroom is on the second floor. There is also a basement where Twilight performs her measurements on Pinkie Pie in Feeling Pinkie Keen. It is also called the Golden Oak Library in Castle Sweet Castle, (the) Golden Oaks Library or Golden Eagle Library in some merchandise, Books and Branches Library at a former Hub website, and Twilight's Library in Gameloft's mobile game.
The tree has a beehive hanging from a branch, a candlestick sign on the front door (sometimes an actual candlestick figure, depending on individual animation errors), a sign of an open book outside the door, and two balconies, one of which has a telescope.
- In Roary and Theodore's Adventures Series, the Golden Oak Library is located near Ffarquhar.
- In some series, the Library has been fixed and rebuilt, while in some it remains in ruins.