The country had a record high of 11,397 new Covid-19 cases and 101 fatalities over the previous 24 hours, the Public Health Ministry reported on Sunday.
There were 11,079 cases in the general population and 318 among prison inmates.
Since April 1, when the third wave of Covid-19 began, there have been 374,523 Covid-19 patients, 256,484 of whom have recovered.
Since the pandemic started early last year, there have been 403,386 Covid-19 cases, 283,910 of whom recovered.
The death toll was at 3,247 in the third wave and 3,341 from the beginning of the pandemic early last year.
The previous high of new daily Covid-19 cases was at 10,082 reported on Saturday.
The Centre for Covid-19 Situation Administration said 60 of the fatalities had been registered in Bangkok, 15 in Samut Prakan and five each in Nakhon Pathom and Pattani. The rest were distributed among 12 other provinces.
Bangkok led all provinces in the number of new cases at 2,166, followed by Pathum Thani (684), Samut Sakhon (677), Chon Buri (660) and Samut Prakan (604).
The nine cases detected in people coming from abroad comprised four arrivals from Cambodia, four from the United Arab Emirates and one case from the United Kingdom.
