The US Defense Department said the total estimated value of the contract is $945,900,000, Anadolu Agency reported.
Under the contract, Lockheed will provide Phase I "long lead items" of the Terminal High Altitude Area Defense (THAAD) missile defense system.
The contract also includes test equipment, key personnel, line requalification activities, initial training development and early engineering development.
In November, President Donald Trump’s administration signed off on a $15 billion deal to sell Saudi Arabia 44 THAAD launchers, missiles and related equipment.
Washington and Riyadh entered formal talks for THAAD in December 2016.