Last week, the central bank made a surprise cut to the policy rate. It also eased capital account restrictions to facilitate cross-border capital flows.
The baht lost more than 1 per cent to 33.43 per dollar on Thursday, its weakest since January 2010.
The central bank governor attributed the depreciation to several factors, including the rate cut, the easing of the capital account restrictions as well as the improvement in some US economic indicators.
He is convinced that the weakening baht would support Thailand's economic recovery, citing that the first-quarter growth was slower than expected due mainly to export contraction.