Demetri Martin’s 2012 book This Is a Book contains a page marked “This page unintentionally left blank.”
The first page of this edition of Jean-Paul Sartre’s 1944 essay Anti-Semite and Jew is marked “This Page Intentionally No Longer Blank”.
At the start of Australian children’s author Andy Griffiths’ 1999 book Just Stupid!, a cartoon snail tells the reader, “This page would be blank if I were not here telling you that this page would be blank if I were not here telling you that …”
Reza Amirkhani’s 2000 novel Man-e-oo contains a whole chapter of blank pages.
Idries Shah’s The Book of the Book spends 10 pages explaining why the pages that follow are important; these pages prove to be blank.
Don Novello’s 1977 book The Lazlo Letters ends with several otherwise empty pages marked “FREE PAPER!”
This 32-page pamphlet, published in 1880, was entirely blank:

It worked — William Gladstone defeated Lord Eskdaill in an upset victory at Midlothian.