The decision comes days after the country introduced a new rule requiring social media firms to set up liaison offices in the country.
TikTok, which has around a billion monthly users, has been banned by several countriesincluding India.
Earlier this year,Montana became the first US state to ban itwhilethe UK Parliament banned it from its network.
Minister for Communications and Information Technology Rekha Sharma has told the BBC Nepali that the platform spread malicious content.
She added that "the ban would come into effect immediately and telecom authorities have been directed to implement the decision".
But Gagan Thapa, a senior leader of Nepali Congress, which is part of the coalition government, has questioned the government's decision to impose a ban on TikTok.
He said it was an attempt to curb the freedom of expression and officials should focus on regulating the platform.
TikTok has come under scrutiny from authorities around the world over concerns that data could be passed to the Chinese government.
Its parent company, ByteDance, has previously rejected the allegation. TikTok did not respond to the BBC's request for comment on the latest ban by the government in Nepal.
Although TikTok lags behind the likes of Facebook and Instagram, its growth among young people far outstrips its competitors.
More than 1,600 TikTok-related cyber crime cases have been registered over the last four years in Nepal, according to local media reports.
According tothe BBC Media Action report on the media usage in Nepal, TikTok is the third most used platform nationally.
While YouTube and Facebook are popular among internet users of all age groups, TikTok is highly popular with younger age groups with more than 80% of social media users aged between 16 and 24 using the platform.
Pakistan has temporarily banned the app at least four times since October 2020 whileits online shopping service was shut in Indonesialast month.
Nepal has banned the Chinese-owned app TikTok because its content "was detrimental to social harmony."