But his appearance will mean an earlier start than is traditional - he has agreed only to a Friday afternoon engagement, sandwiched between other commitments.
The two-week festival will now begin several hours earlier than envisaged, at the King’s Hall on September 29.
It will be followed on its opening night by the broadcaster Stuart Maconie, who has retraced the route of the Jarrow hunger marchers, 80 years on.
Bennett, who is 83 and was last at the Ilkley festival in 2009, is expected to read from his most recent collection of diaries and essays, Keeping on Keeping On.
The festival’s director, Rachel Feldberg said: “Alan reads as only he can. We know him as one of our great writers so it’s easy to forget what a terrific performer he is, too. He was in Beyond the Fringe, after all.
“We are just happy to have him and we would have done whatever we could to accommodate him.”
The festival, which last month saw its Arts Council funding confirmed for the next four years, will also play host to the broadcaster Victoria Derbyshire, whose forthcoming book documents her breast cancer treatment and her decision to share her experience in a series of video diaries which attracted more than 13m viewers.
Another BBC presenter, Evan Davis, will talk about his new book on the proliferation of “fake news” in the Donald Trump era.
The full programme will be unveiled on August 17 and tickets go on sale on August 29.