He was identified as Rajesh Singh, 37, the chief executive officer of Smith English School of Languages in Thanyaburi district, The Bangkok Post quoted a police officer as saying.
Police and rescue workers said that Singh was found hanging by a scarf from the handrail of a staircase that led to his second floor residence.
The housekeeper, who discovered the body, told police that Singh ran the school with his friends but used to stay alone in the house.
"He had lately complained about financial problems," the housekeeper added.
Police will now examine the purported suicide note that they found with the body and interrogate his partners.