The figure rose 8.4% year-on-year to THB606,378 ($18,000), according to a survey by the University of the Thai Chamber of Commerce.
This is the highest level ever recorded since the university first conducted its survey in 2009.
"The high level of household debt is hurting the nation’s attractiveness for investors as it limits consumption and growth in the future," Thanavath Phonvichai, the university’s president, said at a briefing Tuesday, as reported by Bloomberg.
"The government is right on target to address this issue as well as boosting economic growth."
Thailand, the second largest economy in Southeast Asia behind Singapore, has been lagging in GDP growth compared to regional peers.
The government and central bank have expressed concerns over the country's household debt at 90.8% of GDP at the end of March 2024, among the highest in Asia, Reuters reported.
Thanavath said that the household debt-to-GDP ratio is anticipated fall to 89% next year, driven by new stimulus measures, particularly the cash handout scheme, which are expected to stimulate economic growth.