He attended a special event at Belfast City Hall on Thursday morning to mark its start.
He said his wife found out about the scheme online.
“We thought it would be a great opportunity for kids to get a head start,” he said.
“We got the application in as soon as possible.”
Mark said reading to their kids is normal for his family.
“We have an older child too, we’ve been reading with him all the time, he loves it and I’m sure she will too.”
The Imagination Library is a reading scheme first launched in Tennessee where Parton grew up and is celebrating its 30th anniversary this year.