SIA decided to restore its five daily flights between the Thai capital and the island republic after cutting them to three or four a day in the first four months of 2014.
"We reverted to the old frequencies as demand began to pick up with the improved sentiment for travel to Bangkok," SIA's Thailand general manager Ong Cheow Teck told the Bangkok Post.
Several airlines have seen a revival in passenger traffic through Bangkok after a state-of-emergency decree was lifted in March and politically motivated violence eased.
SIA cancelled more than 40 Bangkok-Singapore flights in the first two months of the year to suit travel demand depressed by civil unrest in Bangkok, marking the highest number of cancellations by any international carrier during the political crisis.
With the return of its normal frequencies, SIA offers nearly 3,000 seats a day both ways between Bangkok and Singapore, believed to be the most offered by a single airline on the route.