The baht strengthened to a one-year high of 29 baht per U.S. dollar on Wednesday morning before returning to around 30 baht later in the day.
Currencies across the region had been affected by news on COVID-19 vaccines and a sharply weakening dollar, assistant governor Vachira Arromdee said in a statement.
"The Bank of Thailand was not complacent about currency movement and came in to manage it to reduce volatility that would affect economic adjustments," she added.
The bank would continue to monitor financial markets closely, she said.
(Reporting by Chayut Setboonsarng and Satawasin Staporncharnchai; Editing by Andrew Heavens)
