The 30 year old signed a four year deal and became manager Steve Bruce’s eighth signing of the summer.
Again, the see is undisclosed.
O’Shea said: “Once I’d heard reports about the club and the people here, the ambitions and what the manager was all about, it was the only place for me.”
Steve Bruce added: “John has been a solid, consistent part of United’s squad for well over a decade, which goes to show the fantastic pedigree of player we have signed.
“He is a wonderful professional both on and off the field and his wealth of experience and versatility will be great attributes for us.”