Deputy National Police chief Somyot Poompanmoung said members of the group, belonging to an international Mafia network, were nabbed in southern resort island of Phuket and flown to Bangkok for questioning.
The suspects included Joseph Manuel Hunter, a former US Navy Special Forces officer, two British nationals, a Slovakian, a Filipino and a Taiwanese.
Pol Gen Somyot said Thai police were earlier tipped off by their US counterparts on the gang members who had been in hiding in Thailand. They entered Phuket on September 6.
Narcotics Suppression Police commander Chaiwat Chotima said the suspects had been involved in smuggling and exporting various kinds of drugs including crystal methamphetamine, cocaine and heroin with a global connection.
The group has also been involved in other illegal activities including sex trade in many countries, he said.
All suspects will be deported to the US for trial, the police added.