The F-35, formerly known as the Joint Strike Fighter, is being built by the US defence giant in partnership with other countries, including the UK.
Lockheed Martin reported a 5% rise in second-quarter profits to $942m.
The company also raised its sales and profit forecasts for 2017.
The company said sales in its aeronautics business, its most important division, were up by almost 20% in the second quarter of the year.
The F-35 programme is the US defence department's most expensive, something President Donald Trump singled out last year for criticism.
The UK has so far ordered 24 of the jets, the first of which are due to go into service with the RAF and the Royal Navy next year.
The short take-off and vertical landing planes, which will be known as the Lightning II, are set to be deployed on the UK's two new Queen Elizabeth class aircraft carriers.
Increased sales of the F-35 fighter jet have helped Lockheed Martin, the biggest supplier of defence equipment to the US military, to report better-than-expected profits.