There were 23 more Covid-19 fatalities and 3,398 new cases registered during the previous 24 hours, the Public Health Ministry said on Monday morning.
There were 3,396 cases in the general population and two among prison inmates.
This compared with 20 coronavirus-related fatalities and 3,787 new cases reported on Sunday morning.
On Sunday, 5,467 Covid-19 patients were discharged from hospitals after recovering from the coronavirus.
Since the pandemic started early last year, there have been 2,172,044 Covid-19 cases, with 2,101,326 complete recoveries so far.
The vast majority of the Covid cases and deaths have occurred since April 1, around when the third wave of Covid-19 began.
The death toll stood at 21,100 during the third wave and 21,194 since the beginning of the pandemic.
The kingdom's 24-hour high of Covid-19 fatalities was 312 recorded on Aug 13. The highest number of cases was 23,418 on Aug 13.
Taweesilp Visanuyothin, spokesman for the Centre for Covid-19 Situation Administration, said in the afternoon briefing that the latest 23 deaths were aged 43 to 87 years.
Bangkok reported two more deaths while another was reported in the adjacent province of Pathum Thani.
Other central plain provinces further from the capital recorded five more deaths - in Chon Buri (2), Chanthaburi (1), Trat (1) and Saraburi (1).
The Northeast had three more fatalities - in Kalasin (1), Nakhon Ratchasima (1) and Udon Thani (1).
The South reported eight more deaths - in Trang (2), Pattani (1), Satun (2), Phangnga (1), Yala (1) and Songkhla (1).
The North saw four more fatalities - in Phitsanulok (1), Lampang (2) and Mae Hong Son (1).
The 3,398 new cases included 3,376 local infections and 20 imported cases.
Of the local infections, 3,368 were confirmed at hospitals and eight via mass testing.
Bangkok had 604 new cases, followed by 200 in Nakhon Si Thammarat, 150 in Songkhla, 129 in Chon Buri, 118 in Surat Thani, 105 in Prachuap Khiri Khan, 94 in Ayutthaya, 85 in Chiang Mai and 72 each in Pattani and Trang.
“New infections are declining,” Dr Taweesilp said.
The 20 imported cases were from France (3), Russia (4), Ukraine (1), United Kingdom (3), the United States (1), Germany (2), Denmark (1), Switzerland (1), Japan (1) and Laos (3).
On Sunday 49,524 people received Covid-19 treatment at hospitals (down from 51,616 on the previous day), including 1,061 seriously ill patients (down from 1,105) and 307 dependent on ventilators (down from 309).
Global Covid-19 cases rose by 432,228 in 24 hours to 270.43 million. The worldwide death toll went up by 3,988 to 5.32 million. The US had the most cases at 50.80 million, up 38,784, and the most deaths at 817,956, up 167.
