Isa Barkaj and Isaac Shakila were convicted of shooting Laurent Barbot, a technical assistant for French electronics group Thales, on September 26th, 2004, said a statement published by the official SPA news agency.
No details were given on the circumstances surrounding their arrest or of their trial.
Barbot's murder was the first of a French national in the kingdom during a deadly wave of attacks on the Gulf state between 2003 and 2006, blamed on Al-Qaeda.
Those shootings and bombings killed more than 150 Saudis and foreigners.
Authorities set up specialized courts in 2011 to try dozens of Saudis and foreigners accused of belonging to Al-Qaeda or of participating in the attacks.
Barkaj and Shakila were also convicted of plotting to assassinate foreign officials in the kingdom, as well as tracking and opening fire on a vehicle belonging to one consulate, the statement said.
They had also agreed to target other foreigners in Saudi Arabia.
Thursday's executions in Jeddah bring to 123 the number in the kingdom this year, compared with 87 for the whole of 2014, according to AFP tallies.
Amnesty International says Saudi Arabia is one of the world's most prolific executioners, along with China, Iran, Iraq and the United States.
Under the conservative kingdom's strict Islamic sharia legal code, murder, armed robbery, rape, drug trafficking and apostasy are all punishable by death.
Executions in Saudi Arabia are almost always carried out by beheading.