Saudi national Daifallah al-Omrani was executed in the northern region of Tabuk after his conviction for smuggling amphetamines, the interior ministry said.
In a separate case, Yemeni citizens Ahmed Mubarak and Abdul Salam al-Jamali were executed in the southwestern city of Jazan near their homeland, the ministry said.
They were convicted of trying to smuggle hashish.
Most people sentenced to death in Saudi Arabia are beheaded by a sword.
The kingdom executed 47 people in a single day on January 2 for "terrorism".
More From This Section
Amnesty International says the number of executions in Saudi Arabia last year was the highest for two decades.
The kingdom practises a strict Islamic legal code under which murder, drug trafficking, armed robbery, rape and apostasy are all punishable by death.
Rights experts have raised concerns about the fairness of trials in Saudi Arabia, which says the death penalty is a deterrent to crime.