Governor Greg Abbott has issued an executive order banning all entities, including private companies, from enforcing vaccinations in Texas.
Mr Abbott, a Republican, has been one of the most vocal US leaders opposed to making coronavirus vaccines mandatory.
He has made similar edicts since the start of the pandemic, but this is the first to include private employers and their customers.
The governor has called on state lawmakers to pass a ban into law.
“The Covid-19 vaccine is safe, effective, and our best defence against the virus, but should remain voluntary and never forced,” Mr Abbott said in a statement.
The move will pit him against Democrat President Joe Biden, who called on firms last month to introduce mandatory vaccines for their staff.
State executive orders usually carry the force of law, but can be invalidated by a judicial review if they are deemed in violation of state laws and codes.
Earlier this year the governor lifted the state’s mask mandate. He also signed an executive order in August against vaccine mandates by government agencies, including public schools and universities.
But soon after the order, two local courts rules against it and the Texas Education Agency announced that it would not enforce the ban.
Mr Abbott tested positive for coronavirus in August during a state-wide surge of cases of hospitalizations. He credited his quick recovery to being fully vaccinated.
The latest order comes as Mr Abbott faces pressure from two rival candidates in next year’s Republican primary: former state Senator Don Huffines, and former Florida Congressman Allen West. Both competitors are strongly opposed to vaccine mandates.
“[Mr Abbott] knows which the way the wind is blowing. He knows conservative Republican voters are tired of the vaccine mandates and tired of him being a failed leader,” tweeted Mr Huffines.