Miller was offered a new two year deal to stay at Town, however a number of parties were interested in securing the services of the former Hartlepool man, with Sunderland leading the race, and now the Black Cats have got their man.
Millers father and agent, Tommy Miller Snr told BBC Sport: "Subject to him passing his medical next Wednesday, he is signing for Sunderland.
"He had plenty of options, but if he was going to stay in the Championship, he would have stayed with Ipswich.
"I think it is the only club he would have left Ipswich for because he has had a great time down there and played under two very good managers."
Miller is the second player to leave Town for Sunderland this Summer, with Kelvin Davis agreeing a move to the Stadium of Light earlier this week.