The tanks will provide increased range and fuel offload capacity for the plane, which entered its engineering manufacturing development phase last month.
"Cobham is delighted to be working with Boeing to support the KC-46 program," said Iain Gibson, vice president of Cobham Mission Equipment. "Cobham's experienced engineering and program team will design and deliver an innovative Body Fuel Tank design that achieves the technical and schedule demands of the program."
Cobham Mission Equipment, which has headquarters in Iowa, is a unit of Britain's Cobham Plc and is a subcontractor for a number of components for the aircraft's refueling system, including wing-mounted aerial refueling pods.
The value of the contract from Boeing wasn't given but Cobham said each tanker would be equipped with four body fuel tanks.
The Air Force is initially expected to acquire 179 of the tankers, which will be in production through 2028.