The emergency decree is effective until April 30 and is meant to give the government powers to order curfews and travel bans. Provinces have also ordered their own restrictions or shutdowns.
The authorities announced 111 new cases on Thursday, bringing the national total to 1,045 and four deaths. Infections have steadily increased since mid-March, triggering sterner measures by the government to curb the spread of Covid-19, the disease caused by the virus.
The government has also banned entry of all foreign tourists effective on Thursday. Foreign nationals belonging to diplomatic missions and holders of work permits in Thailand are exempt.
Phuket was the first province to issue a curfew on Wednesday, lasting from 5pm till midnight. Locals were urged to stay home while tourists were to stay at their hotels. Alcohol consumption on the island's beaches and other public venues has also been banned.
In Yala, a province bordering Malaysia, travel from and to the province has been banned from midnight on Thursday after a doctor and two nurses tested positive.
Up to 132 Thai nationals from Yala and Pattani, part of the Muslim-majority region in Thailand's deep south, attended a religious gathering near Kuala Lumpur during late February that the authorities say led to large-scale spreading of the virus. About 16,000 people attended the event.
The popular beach town of Pattaya and adjacent Chonburi province, a two-hour drive from Bangkok, also closed shopping malls, dine-in restaurants, parks and sports venues effective on Wednesday. Travels to and from nearby Koh Si Chang island have also been banned.
Known for its wild parties, Pattaya's bars and nightclubs have already been ordered shut since March 18.
Elsewhere across the country, supermarkets and restaurants are exempt from the closure order.
Chiang Mai has shut schools, malls, bars as well as entertainment and sports venues.
The closures come after Bangkok shut down various businesses from March 18 to April 12, from bars and nightclubs, to massage parlours, spas, salons, gyms, schools and universities.
The Thai traditional new year "Songkran", celebrated with water splashing and festivities during April 13-15, has also been cancelled.
The orders came after Thailand saw continuous jumps in Covid-19 cases since March 15.
Many of the cases involved outbreaks at a Bangkok boxing stadium on March 6 that spread to other boxing rings across the country, and bars and nightclubs in the capital.
Covid-19 infections have spread to 47 other provinces out of the country's 76 provinces including Bangkok.