Bangkok and Phetchaburi led the list at 1,356 cases each, followed by 555 in Phetchaburi, 358 in Samut Prakan, 327 in Saraburi and 211 in Pathum Thani.
Meanwhile, the Centre for Covid-19 Situation Administration provided no details on the 57 overseas arrivals who tested positive.
Meanwhile, 3,101 patients have recovered and been discharged in the last 24 hours.
As of Monday, the number of confirmed cases in Thailand had risen to 159,792.
So far, 108,345 have recovered and been discharged, 50,416 patients are still in hospitals and 1,031 have died.
Separately, 45,122 people were given their first Covid-19 shot in the last 24 hours, while 16,430 people were given their second shot, bringing the total number of Covid-19 vaccine doses administered in Thailand to 3,609,882.
According to Worldometer, as of 11am on Monday, the number of confirmed cases globally had risen to 171.02 million (up by 398,811), 153.11 million of whom have recovered, 14.36 million are active cases (92,059 in severe condition) and 3.55 million have died (up by 8,319).
Thailand ranks 82nd on the global list of most cases, which is topped by the US with 34.04 million, followed by India 28.04 million, Brazil 16.51 million, France 5.66 million and Turkey 5.24 million.