Yaser Qawza broke into the home of his Saudi employer Falwa al-Jarad, tied her up and beat her to death before robbing her money and jewellery, according to an interior ministry statement.
Qawza was executed in the southern region of Aseer, said the statement, published by the official SPA news agency.
Most executions in the country are carried out by beheading with a sword.
Last year Saudi Arabia executed 153 people, most of them for drug trafficking or murder, according to an AFP tally.
The kingdom practises a strict Islamic legal code under which murder, drug trafficking, armed robbery, rape and apostasy are all punishable by death.
On January 2, the kingdom executed 47 men convicted of "terrorism", including Al-Qaeda-linked Sunni militants and Shiite cleric Nimr al-Nimr, whose death sparked a diplomatic crisis with Iran.
