It was the latest major bust on a well-worn smuggling route.
Mohd Nizam Bin Ishak, 34, was stopped on Monday while driving a truck with fake Malaysian licence plates at a border checkpoint at Sadao in Thailand's province of Songkhla.
Investigators said they found 520 kilograms of marijuana worth around USD 440,000 hidden under furniture in the back of the truck.
"The suspect confessed to the trafficking charge and said he was hired for 1,000 ringgit ($257) to transport marijuana from Hat Yai (in Songkhla) to a warehouse in Kuala Lumpur," police Lieutenant General Rawat Klinkasorn said in a statement.
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Thailand is both a producer and major transit hub for drugs.
Much of the regional drug manufacturing takes place in the Golden Triangle, a remote border area where Myanmar, Laos and Thailand meet.
Major General Chartee Paisarnsilp, divisional commander of the narcotics suppression police, told AFP the cannabis came from a neighbouring country but declined to say which.
Thai police last month announced a major bust involving a Malaysian gang allegedly smuggling millions of dollars of heroin and methamphetamine between the two countries by train.
Drugs usually sell for a significantly higher price in Muslim-majority Malaysia, making it a tempting prospect for criminals.
Police forces in Thailand, Myanmar, Laos and Malaysia often announce drug smuggling busts that usually catch mules or low-paid members of criminal gangs.
But arrests of cartel leaders and kingpins are much rarer, with many of the region's biggest players staying in business for decades.