The Pride & Prejudice author is thought to have made the handwritten entries in the record book while a teenager in Hampshire in the late 18th Century.
Hampshire Archives, which holds the Steventon marriage register for 1755-1812, says Austen had access to the book because her father, George Austen, was the rector of the parish.
The records will go on display in May.
The little-known document includes a fictitious entry for the publication of banns between Henry Frederic Howard Fitzwilliam of London and Jane Austen of Steventon.
Another fake entry details the marriage of Edmund Arthur William Mortimer of Liverpool and Jane Austen of Steventon.
It is not known whether either Fitzwilliam or Mortimer actually existed.
Hampshire County Council's culture spokesman Andrew Gibson said: "In the year when we celebrate 200 years since her death, this unique document uncovers another side to Jane Austen's character.
"Jane would have been in her teens when she wrote these fake marriage entries, and some could say it reveals a mischievous side during her younger years."
The documents will go on display in May as part of the Mysterious Miss Austen exhibition at Winchester's Discovery Centre, which marks 200 years since the author's death at the age of 41.
Novelist Jane Austen created fake entries in a marriage register linking herself with two separate men, it has emerged.