There were 29 more Covid-19 fatalities and 3,370 new cases registered during the previous 24 hours, the Public Health Ministry said on Wednesday morning.
There were 3,259 cases in the general population and 111 among prison inmates.
This compared with 37 coronavirus-related fatalities and 2,862 new cases reported on Tuesday morning.
On Tuesday, 4,557 Covid-19 patients were discharged from hospitals after recovering from the coronavirus.
Since the pandemic started early last year, there have been 2,178,276 Covid-19 cases, with 2,110,701 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 21,166 during the third wave and 21,260 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.
Sumanee Wacharasin, hazard communication director of the Department of Disease Control, said the 29 latest fatalities were aged 23 to 93 years and included one foreigner, a Myanmar national. Twenty-one of them were not vaccinated.
The fatalities included a pregnant woman, 43, in Chon Buri, who had diabetes and was not vaccinated.
Dr Sumanee said the vaccination rate was lowest among pregnant women and the majority of infected pregnant women died along with their foetuses.
Bangkok logged three new deaths while another was reported in the adjacent province of Samut Prakan.
Other central plain provinces further from the capital recorded six more deaths - in Chon Buri (2), Prachuap Khiri Khan (1), Rayong (1), Lop Buri (1) and Sa Kaeo (1).
The Northeast had four more fatalities - in Khon Kaen, Chaiyaphum, Nakhon Ratchasima and Buri Ram.
The South reported 12 more deaths including four in Nakhon Si Thammarat (the most new fatalities) and three in Surat Thani.
The North saw three fatalities - in Mae Hong Son, Chai Nat and Uttaradit.
The 3,370 new cases included 3,239 local infections and 20 imported cases.
Of the local infections, 3,161 were confirmed at hospitals and 78 via mass testing.
Bangkok had 583 new cases, followed by 172 in Chon Buri, 150 in Nakhon Si Thammarat, 140 in Samut Prakan, 135 in Songkhla, 117 in Pattani, 97 in Surat Thani, 89 in Chiang Mai, 76 in Prachin Buri and 71 in Trang.
“New infections in our country are falling as expected,” Dr Sumanee said.
However, there were still new clusters at factories and workplaces in Khon Kaen, Rayong and Prachin Buri; at markets in Chanthaburi, Sa Kaeo and Lop Buri; at a military camp in Prachuap Khiri Khan; at funerals in Narathiwat and Khon Kaen; and at eateries in Bangkok and Surat Thani.
“Clusters of new infections may grow during long holidays especially at markets and eateries, especially at grilled pork places where customers share pans and stay a long time,” Dr Sumanee said.
The 20 imported cases were from Cambodia (2), the United States (2), Ethiopia (1), Malaysia (2), France (2), Findland (1), Germany (1), Norway (2), Belgium (1), the United Kingdom (3), Australia (1), Denmark (1) and Switzerland (1).
On Tuesday 46,315 people received Covid-19 treatment at hospitals (down from 47,531 the previous day), including 1,018 seriously ill patients (down from 1,039) and 277 dependent on ventilators (down from 296).
Global Covid-19 cases rose by 608,382 in 24 hours to 271.72 million. The worldwide death toll went up by 7,271 to 5.34 million. The US had the most cases at 51.14 million, up 108,566, and the most deaths at 821,335, up 1,598.
Dr Sumanee said Omicron infections had been confirmed in 70 countries and were spreading fast in the United Kingdom, Denmark and Norway. China confirmed its first Omicron case in an arrival, she said.
The government confirmed eight Omicron cases with others suspected. They comprised 0.23% of Covid-19 infections in the country since Nov 1, while Delta infections accounted for 99.58%, Alpha 0.17% and Beta 0.02%, Dr Sumanee said.
Since the country's reopening on Nov 1 a total of 236,324 visitors had arrived by air and about 80% of them entered via the Test & Go scheme, as of midnight.
Covid-19 infection rates among them rose slightly from 0.13% last month to 0.18% so far this month, she said.