CCTV from a phone shop in the Tukcom computer centre in Pattaya showed a foreigner take a phone and try to escape yesterday evening.
Staff chased the man and a citizen's arrest was made.
Captain Janephop Wanthongsang said Laurent Meriem, 40, was taken to Pattaya police station.
The Huawei P30 Pro, costing Bt31,900, was reportedly recovered.
The suspect was charged with theft and illegal entry into Thailand.