That's what the National Literacy Trust says.
Poorer children and boys were less likely to have books, it added.
The survey was carried out in September with school-aged children from 111 schools across the UK.
It suggested that a third (33.2%) did not have books of their own. That translates to 3.8m children UK-wide.
I write books. My latest is a YA science fiction novel called Homeland (it's the sequel to Little Brother). More books: Rapture of the Nerds (a novel, with Charlie Stross); With a Little Help (short stories); and The Great Big Beautiful Tomorrow (novella and nonfic). I speak all over the place and I tweet and tumble, too.