The contract, which was signed on 9 July, includes aerodrome, approach and engineering services, as well as the addition of services for MOD St Athan for the first time.
The contract award follows significant passenger growth at Wales’ national airport since it came under public ownership in 2013.
Deb Barber, CEO at Cardiff Airport, says: “After a robust tender process, we were very impressed by the NATS bid.
"Not only are they a reputable, trusted supplier of air traffic services at many UK airports but they also stand out for demonstrating technological innovation, operational excellence and impressive engineering capabilities.
“We look forward to developing further our partnership with NATS over the next ten years and, on behalf of Cardiff Airport’s team, I’d like to congratulate NATS on their success.”
NATS CEO, Martin Rolfe, enthuses: “Cardiff Airport has gone from strength to strength in recent years, achieving over 60% passenger growth.
"We are delighted to be adding MOD St Athan to the NATS family and look forward to continuing to provide the Welsh capital city airport with an outstanding service, as we have done since the 1960s.”