The Mali youth international has joined from Guidars FC in his homeland.
Kone only turned 18 in February and will initially be supported by the Academy in order to give him time to settle into life in Manchester.
He has put pen to paper in advance of the closure of the summer transfer window later this evening (Friday).
Our picture shows Kone being greeted at Carrington by technical director Jason Wilcox.
Welcome to United, Sekou!