Hadian al-Qahtani was found guilty of shooting dead Abdullah al-Qaoud following a dispute, the interior ministry said in a statement carried by state news agency SPA.
Most people executed in Saudi Arabia are beheaded with a sword.
The executions so far this year include 47 for "terrorism" carried out in a single day on January 2.
In 2015, Saudi Arabia executed 153 people, most of them for drug trafficking or murder, according to an AFP count.
The kingdom has a strict Islamic legal code under which murder, drug trafficking, armed robbery, rape and apostasy are all punishable by death.