The ban on unvaccinated travellers will be effective from July 15-31 or until the order changes, Phuket authorities said on Wednesday.
Those vaccinated with AstraZeneca must have had their second jab at least 14 days before arriving in Phuket.
Travellers who have recovered from Covid-19 must show a negative RT-PCR or antigen test taken no more than seven days before entering the province.
Those arriving from the 10 provinces under maximum controls – Bangkok, Samut Prakan, Nonthaburi, Pathum Thani, Nakhon Pathom, Samut Sakhon, Songkhla, Pattani, Yala, Narathiwat – must also download and Bluetooth-enable the MorChana tracing app.