He faces a long jail term or the death penalty, authorities said.
Russian beautician Tatiana Firsova, who allegedly tried to smuggle in 6.6 grams of cocaine, was arrested after arriving in Bali on a flight from Doha last week. She faces up to 15 years if convicted.
The four suspects, wearing orange prison jumpsuits, were paraded together in front of reporters Monday — a common practice in Indonesia.
The arrests come as two Thai men were sentenced last week to 16 years in prison each after they were found guilty of smuggling one kilogram of methamphetamine that they had swallowed.
While death sentences are often reduced to long jail terms, Indonesia has executed foreign nationals in the past, including two Australian masterminds of the Bali Nine heroin gang who were shot in 2015.