The European Commission has banned TikTok on official devices used by staff amid concerns over data protection, a spokesperson said.
The ban also means that European Commission staff cannot use the Chinese-owned video-sharing app on personal devices, including phones, that have official apps installed.
The spokesperson confirmed a report by news website Euractiv.
TikTok said it was disappointed by what it called a "misguided" decision.
Employees must remove the app as soon as possible and should do so by 15 March.
TikTok, whose parent company ByteDance is Chinese, has faced increasing Western scrutiny in recent months over fears about how much access Beijing has to user data.
The US last year banned the app from federal government devices, and some US politicians are trying to prohibit TikTok from operating in the country.
Last month, the Dutch government reportedly advised public officials to steer clear of the app over similar concerns.
In November, TikTok admitted some staff in China can access the data of European users.
TikTok chief executive Shou Zi Chew was in Brussels last month for talks with EU officials during which they warned TikTok to ensure the safety of European users' data.
He insisted the company was working on a "robust" system for processing Europeans' data in Europe, an EU spokesman said at the time.
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TikTok has also promised to hold US users' data in the US to allay Washington's concerns.
In a statement, TikTok said: "We are disappointed with this decision, which we believe to be misguided and based on fundamental misconceptions.
"We have contacted the Commission to set the record straight and explain how we protect the data of the 125 million people across the EU who come to TikTok every month.
"We're continuing to enhance our approach to data security, including by establishing three data centres in Europe to store user data locally; further reducing employee access to data; and minimising data flows outside of Europe."
Meanwhile, Fianna Fáil Senator Malcolm Byrne has called for the company to appear before the Oireachtas Media Committee to discuss its "ongoing concerns regarding data privacy".
