Lyu Yuyong, 48, took 229,000 yen ($2,172) from the bag of the Japanese passenger, only identified as Takahashi, on a flight from Da Nang to Ho Chi Minh City on August 20, the Southern Airports Authority said.
The theft was spotted by the flight crew who handed the Chinese man to security authorities at Tan Son Nhat Airport after the aircraft landed. Airport security officials turned him over to HCMC police for further investigation.
Several Chinese nationals been caught stealing from other passengers aboard flights in Vietnam in recent years.
Vietnam Airlines said the number of in-flight thefts has showed no signs of slowing down for several years now. It has uncovered 20 cases in the first seven months of this year and budget carrier Vietjet Air, 11.
Last year, Vietnam Airlines reported 12 cases of in-flight crime that involved foreign suspects.
Vietnam's aviation industry served more than 56.8 million air passengers in the first half of this year, up 8.4 percent from a year ago.