Gross domestic product grew 11% in the first three months of the year, compared to the previous three months, data showed.
On an annual basis the economy grew 0.3%, after shrinking 8.9% in previous quarter.
Authorities and analysts said the rebound was stronger than expected.
Thailand was hit by some of the worst flooding in decades late last year.
Companies like the Japanese car maker Honda, Western Digital and others were forced to temporarily suspend production. Exports also suffered because flooding damaged products.
However, analysts said government policies were boosting domestic demand.
“Today’s data underscored expectations that the economy’s recovery from last year’s floods is on track,” said Radhika Rao from Forecast in Singapore.
“Acceleration in investment spending due to reconstruction efforts and a sharp jump in inventories have lifted headline growth.”
The National Economic and Social Development Board (NESDB) said it now expects growth between 5.5% and 6.5% this year.