Tomáš Petříček had clashed with the country's pro-Russian President over the use of Moscow's Sputnik V Vaccine before its approval in the EU.
The Czech Republic's pro-European foreign minister has been dismissed after losing a bid to lead his own party.
President Milos Zeman "terminated the duties of Tomáš Petříček in accordance with the Constitution," his office said in a statement.
Petříček had clashed with his rival, Interior Minister Jan Hamacek, over control of the Czech Social Democratic Party.
The former minister had suggested breaking ties with the populist liberal ANO party, led by Prime Minister Andrej Babis.
Hamacek had been calling for the foreign minister to resign, stating that the party should "speak with one voice" ahead of the parliamentary elections in October.
Speaking to reporters, Petříček said he respected the decision of the Social Democratic leadership on the matter.
"The prime minister certainly has no reason to prevent or stop this dismissal, and the head of state has already spoken out [in favour of the dismissal]," he said.
The former minister had vocally opposed suggestions that the Czech Republic should roll out Russia's Sputnik V COVID-19 vaccine before it had been approved by the European Medicines Agency (EMA).
"The safety and health of our citizens come before everything else," Petříček had reiterated.
While in office, he had also clashed with the pro-Moscow Czech President over the participation of Russian companies in the planned expansion of the Dukovany nuclear power plant.
"The minister's office has windows facing east," he added in a Facebook post on Monday.
"Sometimes when you defy physics and other forces, you can look completely calmly and boldly at the west, towards Europe."
"It is no secret that I have not been well regarded by the Prague Presidency for some time," Petříček told reporters.
The 39-year-old politician was appointed foreign minister after parliamentary elections in 2018. His dismissal is the second in just a few days after Health Minister Jan Blatný, who was also criticised for opposing the use of the Sputnik V vaccine.
The current Minister of Culture, Lubomir Zaoralek, is favoured to replace Petříček.
On Monday, Czech authorities began easing its COVID-19 restrictions, by allowing citizens to travel abroad and ending a nighttime curfew.
Primary school children have also returned to lessons under strict conditions, while outdoor farmers' markets, zoos and botanical gardens have reopened.
Despite a decline in new cases of COVID-19, the Czech Republic still has the fourth highest infection rate per capita in the European Union, according to the European Centre for Disease Prevention and Control.