Karen Brahe (1657-1736) was a Funen noblewoman and a great collector of books.

Karen Brahe was the owner of the Funen estate Østrupgård, located just north of Faaborg. She managed the property herself.

In 1681 Karen Brahe inherited her aunt Anne Gøye's library.

In 1701 Karen Brahe founded Odense Noble Virgin Monastery, to which she donated her valuable collection of books. Today the book collection is in Roskilde.

Karen Brahe's book collection is the only preserved nobles book library from the 1700s, and the collection contains about 3400 numbers, several of which are rare and unique.