Carletto Lana shot dead Saudi national Nasser al-Gahtani before running him over with a car, the SPA news agency said.
His execution was carried out in Riyadh.
According to an AFP tally, 80 foreigners and Saudis have now been executed in the country this year, despite international concerns over the number and judicial process.
More than two-thirds of this year's executions have been carried out over the past four months.
Rape, murder, apostasy, drug trafficking and armed robbery are all punishable by death under the kingdom's strict version of Islamic sharia law.