The Republic of Ireland Under-16 international has finalised a move to Meadow Lane after impressing the Magpies managerial team during a short spell with the club's academy last February.
"Despite considerable opposition from a number of first and second division teams, we are delighted to have won the race for his signature, and the lad has committed himself to a four-year deal with the club," assistant-manager Gary Brazil told the club's official website.
"Shane will be a marvellous addition to an excellent crop of scholars we are bringing in this summer.
"He can play either as a central defender or is equally accomplished in midfield.
"This signing underlines the club's commitment to challenge for the best young players and not only in the Nottingham area."