British-Iranian dual national Mohmed Abdulkarim and British citizen Nouman Essghir, both age 24, were charged under the National Security Act, the Crown Prosecution Service said. They are due to appear in court later Tuesday.
Abdulkarim is charged with assisting Iran's intelligence service and Essghir with entering a prohibited place for a purpose prejudicial to the U.K.
RAF Fairford, in western England, has been used by American bombers to strike Iran during this year's war.
Essghir was arrested outside the base on Sept. 27, when armed police officers and army bomb-disposal experts swarmed the rural area. Scores of residents were evacuated from their homes as police and army bomb-disposal experts searched for explosives.
Abdulkarim was arrested in the past week. Six other men have been arrested and released on bail as investigations continue.
British authorities have linked Tehran to the incident, which led the U.S. to pull its bombers from RAF Fairford. Prime Minister Andy Burnham said that the apparent plot was "almost certainly" directed by Iran's Revolutionary Guard.
Iran has denied involvement, although it has previously said that it considers any base used to attack its territory a legitimate target.