There were 5,126 new Covid-19 cases and 53 more fatalities registered during the previous 24 hours, the Public Health Ministry reported on Tuesday morning.
There were 5,022 cases in the general population and 104 among prison inmates.
The number of new cases fell from 6,428 announced on Monday, when the country recorded 49 more deaths.
On Monday, 7,748 Covid-19 patients were discharged from hospitals after recovering from the coronavirus.
Since April 1, when the third wave of Covid-19 began, Thailand has treated 2,047,272 Covid-19 patients, 1,945,127 of whom have recovered to date.
Since the pandemic started early last year, there have been 2,076,135 Covid-19 cases, with 1,972,553 complete recoveries so far.
The death toll stood at 20,395 during the third wave and 20,489 since the beginning of the pandemic.
The 53 latest fatalities were aged 27 to 104 years and included five Myanmar nationals.
Bangkok recorded five new deaths and a further three were reported in the adjacent province of Samut Prakan.
Other central plain provinces further from the capital reported seven more deaths - in Rayong (3), Phetchaburi (2), Kanchanaburi (1) and Chon Buri (1).
The Northeast had six fatalities - in Buri Ram (2), Amnat Charoen (2), Chaiyaphum (1) and Nakhon Ratchasima (1).
The South reported 22 more deaths – in Pattani (6), Songkhla (6), Surat Thani (4), Yala (2), Nakhon Si Thammarat (2) and Satun (2).
The North saw 10 more fatalities – in Tak (4), Chiang Rai (2), Chiang Mai (1), Phetchabun (1), Nakhon Sawan (1) and Uttaradit (1).
The 5,126 new cases included 5,014 local infections and eight imported cases. Of the local infections, 4,891 were confirmed at hospitals and 123 via mass testing.
Bangkok had 765 new cases, followed by 456 in Songkhla, 330 in Nakhon Si Thammarat, 266 in Surat Thani, 197 in Chiang Mai, 158 in Pattani, 147 in Chon Buri, 128 each in Trang and Samut Prakan and 115 in Ubon Ratchathani.
The eight imported cases were from Sweden (1), the United States (1), Kuwait (1), Bangladesh (1), Belgium (1), Austria (1) and Cambodia (2).
Since the country reopened to visitors on Nov 1, 90,737 people arrived by air and 118 of them (0.13%) tested positive for Covid-19, as of midnight.
On Monday 83,093 people received Covid-19 treatment at hospitals (down from 85,768), including 1,535 seriously ill patients (down from 1,595) and 363 dependent on ventilators (down from 382).
Global Covid-19 cases rose by 448,712 in 24 hours to 258.39 million. The worldwide death toll went up by 5,557 to 5.17 million.
The United States had the most cases at 48.74 million, up 74,156, and the most deaths at 794,864, up 516.
Thailand ranked 23rd globally with 2,076,135 accumulated Covid-19 cases, up from 24th on Monday.